The term "Japanese domestic market" ("JDM") refers to Japan's home market for vehicles and vehicle parts.^[1] Japanese owners contend with a strict motor vehicle inspection and grey markets. JDM is also used as a term colloquially to refer to cars produced in Japan but sold in other countries. JDM does not necessarily refer to the market that the vehicle is destined for.

The average age of JDM cars is 8.7 years, ranking 9th in a survey of 30 of the top 50 countries by gross domestic product.^[2] According to the Fédération Internationale de l'Automobile, a car in Japan travels a yearly average of over only 9,300 kilometres (5,800 mi), less than half the U.S. average of 19,200 kilometres (11,900 mi).^[3]

Japanese domestic market vehicles may differ greatly from the cars that Japanese manufacturers build for export and vehicles derived from the same platforms built in other countries. The Japanese car owner looks more toward innovation than long-term ownership which forces Japanese carmakers to refine new technologies and designs first in domestic vehicles. For instance, the 2003 Honda Inspire featured the first application of Honda's Variable Cylinder Management. However, the 2003 Honda Accord V6, which was the same basic vehicle, primarily intended for the North American market, did not feature VCM, which had a poor reputation after Cadillac's attempt in the 1980s with the V8-6-4 engine. VCM was successfully introduced to the Accord V6 in its redesign for 2008.

In 1988, JDM cars were limited by voluntary self-restraints among manufacturers to 280 PS (276 hp; 206 kW) and a top speed of 300 km/h (186 mph), limits imposed by the Japan Automobile Manufacturers Association (JAMA) for safety. The horsepower limit was lifted in 2004 ^{[citation needed]} but the speed limit of 180 km/h (112 mph) remains.

For many years Japan had severe restrictions on the maximum power and speed that motorcycles could have.

All motorcycles for the Japanese domestic market were restricted to 180 km/h (112 mph).

Power restrictions were as follows ^[4]

• 250cc class: 45 hp (46 PS; 34 kW)
• 400cc class: 60 hp (61 PS; 45 kW)
• 750cc class: 77 hp (78 PS; 57 kW)
• over 750cc: not allowed

• 250cc class: 40 hp (41 PS; 30 kW)
• 400cc class: 53 hp (54 PS; 40 kW)
• 750cc class: 77 hp (78 PS; 57 kW)
• over 750cc: allowed, but restricted to 100 hp (101 PS; 75 kW)

Japanese carmakers do not use a vehicle identification number as is common overseas. Instead, they use either a frame number, chassis number, or vehicle ID number and also a model code as well as an emissions code to identify their vehicles. The frame number identifies the vehicles model and serial number. For example, frame number SV30-0169266 breaks down as "SV30" identifying the model as Toyota Camry/Vista and "0169266" being the serial number of the vehicle. The model code designates the vehicle's model number and features. As an example, ST205-BLMVZ breaks down as "ST205", which means it is a third generation Toyota Celica GT-FOUR, and "BLMVZ" which designates a set of features incorporated in the vehicle. The Emissions Code refers to the vehicle's designated emission standard at the time, usually being placed before the vehicle's model number, and with the five most commonly used designations being E, GF, GH, ABA, and CBA. These codes are only seen on JDM models and are not present on exported models of the same type. Examples would include E-EK9 or GF-EK9 from the first generation Civic Type R, E-BNR32 from the R32 Skyline GT-R, E-JZX100 from the eight generation Mark II. Another useful example to help differentiate between pure JDM models and export examples is the code JHMEEG6 on the European Civic VTi models and E-EG6 on the Japanese fifth generation Civic SiR trims. Correct identification of the chassis code using these markers would help prove the authenticity of the model.

In the '90s the JDM power restrictions along with license restrictions that made it difficult to be licensed on larger motorcycles resulted in a number of models that were not offered anywhere else in the world, with 250cc and 400cc miniature replicas of the bigger 750cc & 900cc bikes.

At the same time, Japan had particularly tough laws regarding road licensing and sales regulations. Any motorcycle more powerful than 250cc had to take an extensively stringent test every two years.

Combining these factors with a virtually non-existent second-hand market made it economic to export the nearly new bikes abroad where they were eagerly bought and a number of import specialists sprung up to cater for this "grey import" market of relatively inexpensive but interesting motorcycles.

In the later '90s as Japan's economy fell into recession it became less profitable to export and Japanese owners held on to their bikes for longer. The last global crash all but ended the "grey import" industry with the big specialist importers closing down.

Cars manufactured for the Japanese domestic market have been growing in popularity since the late 1990s.^[5]

Ex-Japan Imports are also very common in New Zealand where 59% of vehicles registered on New Zealand roads originated from overseas markets as opposed to 41% of which were delivered NZ-New. Of this, 94% originate from Japan.^[6] New Zealand imported an average of 134,834 JDM vehicles per year in the period 2015–2019,^[7] the majority of which were Mazda 3 (Axela), Suzuki Swift, Nissan Tiida, Toyota Corolla and Mazda 2 (Demio).^[8] Other models popular for importation in previous years include exotic vehicles (Honda Torneo, Nissan Skyline, Nissan Laurel and Toyota Altezza), and kei cars (Suzuki Carry, Daihatsu Move, Subaru R2). Due to the popularity of used imports from Japan, and their relatively poor crash-test ratings, the New Zealand Ministry of Transport is currently investigating tougher restrictions on imported vehicles, most notably on the importation of the Toyota Corolla, Mazda 2 (Demio) and Suzuki Swift.^[9]

In 2004, importing JDM cars became popular in Canada as highly sought after vehicles, such as the 1989 Nissan Skyline GT-R, became eligible to import under Canada's 15-year rule.^[10] In contrast, importing grey market vehicles into the United States is much more difficult.^[11] To avoid regulatory problems, most private individuals wait until EPA restrictions no longer apply to the desired vehicle, which is done on a rolling 25-year cycle.^[12]

Ex-Japan import rolling stocks in all kinds is no exception on this list, although it can be considered as JDM but in special case since this was also intended for Japanese market which were mostly acquired by leading private railway companies across Japan such as Japan Railways, even subways such as Tokyo Metro, Tokyu Corporation, Toei Subway and so forth which was in demand for modernizing railway system in most developing countries such as Indonesia, Thailand, and Myanmar to acquire used trains from Japan rather than procuring brand-new rolling stocks, there are some cases that the management from each respective railway companies in Japan such as Japan Railways are decided to donate them to the oversea country, instead of scrapping them ahead in no time, which is really needed for a major upgrade and sign their agreement that the recipient of the oversea country will pay for its freight expenses and the rest will be free. Here are different categories of used rolling stocks listed which were mostly shipped and operated overseas in different countries.

• Electric Multiple Unit

• Diesel Multiple Unit

• Passenger Cars
• Locomotives

Outside of Japan, there are various shops which they sell various kinds of used items from Japan. Philippines is one of the known countries outside Japan to set up a retail outlet called, "Japan Surplus Shop" which is found in most towns of the country. They used to sell used appliances, furnitures, gadgets, accessories, and even bicycles designed for women, are still much more preferred by local buyers because of being more affordable than buying those newly locally made home furnitures, or even new gadgets which is becoming more dominating mostly coming from China and so forth. Most of these items depending on the condition.

In the early 1990s, Ex-Japanese buses had been rising popular and been common in the developing cities across Asia such as Manila, Philippines, Jakarta, Indonesia & even Yangon, Myanmar.

Like in the Philippines, direct importers near ports in Subic, Zambales & Cagayan Valley have started their auction business to import quality vehicles preferably from Japan. And then so, most of the clients who are mostly operating bus companies based in Manila, Philippines began their interest to grow their transport business thru buying Japan surplus buses from all cities in Japan which are definitely cheaper than buying brand-new ones which are mostly imported from other countries and some are locally assembled coach bodies but still at an expensive price.

Used buses like in the Philippines also requires to convert from RHD to LHD conversion which is in compliance with the Philippine traffic law called Republic Act No. 8506 entitled "An act banning the registration and operation of vehicles with right-hand steering wheel in any private or public street, road or highway, providing penalties therefor and for other purposes." A violation of this law is punished by imprisonment for a period from two years, four months, and one day, up to four years and two months, plus a fine of 50,000 pesos (approx. $1,000). And most of the used buses from Japan in Manila, Philippines are mostly operating within the city and intercity travel which are at least 10 years of age after being phased out in Japan.^[13]

As early also in the 1990s, there is no exception that there will be a Japanese domestic market trucks to be called as "Japan Surplus Trucks" for auction & export to any of the developing cities in Asia and even including Russia. Most of the Japanese domestic market trucks that have been exported are Isuzu, Mitsubishi Fuso, Hino and some are Nissan Diesel. These trucks are also proven much reliable and durable since domestic trucks in Japan has no exception for the 10 to 15 year phased out due to the compliance of Japan's existing traffic & environmental regulations and also to avoid any taxes once any domestic truck unit surpassed the age limit to be phasing out.

Japanese domestic market trucks, or 'surplus trucks' after being phased-out in Japan, are extremely popular in the Philippines such as Isuzu Elf, Isuzu Forward, Isuzu Giga, Mitsubishi Canter, Mitsubishi Fuso Super Great & Hino Profia since they are popularly cheaper than buying a brand-new Japanese trucks which are locally distributed and even brand-new trucks from China which is about thrice as expensive as an ordinary used Japanese domestic truck units. Auctioneers in the Philippines also started importing trucks in the 1990s and it had been a staple for every small to medium business enterprise owner particularly in the logistics industry to support and to grow their respective businesses as well aside from being cheap than buying new ones, but also really proven that they are built to last.

Another category for Japanese trucks are the smallest ones, or to be called as kei truck, they are also extremely popular in the Philippines once again to be called as "multicab" which are often reconditioned & converted to any public transportation vehicle like jeepney since they are lighter, more economical, more environmentally friendly than the conventional Philippine jeepneys which are mostly powered by used diesel engines from Japan.

Truck engines from Japan also became a boom hit among small workshops and mostly being supplied by local manufacturers in the Philippines which they made Philippine Jeepneys since the 1980s. Popular truck engines being supplied are Isuzu & Mitsubishi Fuso Canter, sometimes, depending from the local clients, they often requested to supply diesel engines from Mazda and Nissan to install them not just for jeepneys, but also called as AUV which is being used for daily commercial use or can be for private use who often they don't have enough budget than buying a brand-new AUVs offered in the Philippine market during those times such as Toyota Kijang, Mitsubishi Adventure, Mitsubishi L300 van or even Isuzu Crosswind

For a couple of decades, JDM specification model of vehicles often included a speed chime (ja:速度警告音) which rings when a driver exceeds 105 km/h (65 mph) for standard cars and 85 km/h (53 mph) for kei cars. This speed chime was first mandated on November 21, 1974, according to Article 1 of the "Ministerial Ordinance for Partial Revision of Safety Standards for Road Transport Vehicles". Under pressure from the United States and other foreign producers, this requirement was removed in 1986 with "Ministerial Ordinance for Partial Revision of Safety Standards for Road Transport Vehicles" (Ministry of Transport Ordinance No. 3 of 1986) as being a non-tariff barrier. An additional problem was that the repetitive sound could induce sleep in drowsy drivers. Some models used electromechanical glockenspiel-type systems, while other models used a buzzer. Due to that, nickname for speed chime is kinkon (キンコン), an onomatopoeia for a clanging sound.

Several manufacturers continued to offer speed chimes as an option until the early 2000s. The last vehicle to come with the speed chime as standard factory fitment was the Honda City GA1/GA2.^[14]

Initial D anime features this speed chime prominently on Takumi Fujiwara's AE86.

JDM specification model of trucks (over 5 ton loading capacity, 8 ton gross vehicle weight) was mandated to have speed indicator installed from August 1967, according to Article 48 of the Ministerial Ordinance "Safety Standards for Road Vehicles" based on the provisions of Chapter 3 of the Road Vehicle Law.

The speed indicator light is only mandated for large trucks and is not necessary for small and medium-sized trucks and large buses, but installation on these vehicles are not prohibited. Speed indicator is installed in front of the cab, or up in the roof.

Article 48 of the Ministerial Ordinance "Safety Standards for Road Vehicles" based on the provisions of Chapter 3 of the Road Vehicle Law for speed indicator light is as following (modified and also translated):

1. The speed indicator device shall be of a structure that automatically turns on the following number of lights (thereinafter referred to as "speed indicator lights") when traveling at the speeds listed in the table below.
   1. 40 km/h or less (*): 1 light
   2. Over 40 km/h up to 60 km/h: 2 lights
   3. Over 60 km/h: 3 lights
2. The speed indicator lamp shall not be equipped with a manual switch or the like that can easily turn off the speed indicator lamp, except for the power switch of the vehicle.
3. The number of speed indicator lights that are on must be visible from a distance of 100m ahead.
4. The light color of the speed indicator lamp shall be yellow-green.
5. The display of the speed indicator lamp must be free of significant error when driving on flat paved roads.
6. The speed display device shall be equipped with a light or other device that enables the driver to confirm its operating state from the driver's seat (usually they are located on speedometer).

Patterns for speed indicator is as following:

Enacted in 1967, this obligatory speed indicator light has proved a non-tariff barrier for European and American manufacturers. Imported heavy-duty trucks had to be modified to meet this certification requirement. Additionally, most people on Japanese roads never knew how to interpret the speed indicator lights. Therefore, this requirement was abolished in 2001.^[15][16] Instead, truck manufacturers now have to install speed limiters which activate at around 90 km/h (56 mph).

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Some car enthusiasts like to build replicas of JDM vehicles from locally available cars. For example, enthusiasts in the USA will often take a US-market Honda Civic (sixth generation), convert it from left-hand-drive to right-hand-drive and source the required parts such as the engine and gearbox from the JDM EK9 Type R - which is based on the same platform - in order to make an 'exact' copy. Other forms of "JDM Conversions" include converting a USDM model first generation Subaru Impreza and fitting JDM STi parts to make it seem as if it is a genuine WRX STi model. In Southeast Asia, it is common practice to convert a base model Mitsubishi Lancer and swap out the necessary parts, right down to the cutting of the floor pan, and create a Lancer Evolution copy.

However, cars such as this would not be authentic JDM cars as they would possess a United States vehicle identification number.^[17] It is also to be noted that, even with such modifications, it is impossible to recreate the running performance of the original car, as there are many engineering aspects which cannot be replicated by means of "conversion" alone. A good example would be body strengthening methods using spot welding and extra reinforcement on strut mounting points, stress areas in joints, etc. as found in the Lancer Evolution and EK9 Type R models. These reinforcements are not present on base model sixth generation hatchbacks and Mitsubishi Lancers. Hence, replicas or conversions would be similar from a visual standpoint only, as they lack the same level of structural rigidity as the original counterpart.

• Automotive industry in Japan

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