Volkswagens based on this platform have been colloquially referred to by generation number, e.g. the first Golf version (A1) is referred to as a Mark 1 Golf." Often each generation is designated by substituting "Mark" for "A," but this can be misleading. For example, the Mk1 and Mk2 Scirocco are both based on the A1 platform. Furthermore, confusion was possible with the Volkswagen Passat, which has been produced on both the B platform alongside the Audi A4, as well as the A platform depending on the generation. Volkswagen has never used the Mark or Mk designations.
Volkswagen Group introduced a new alphanumeric nomenclature for vehicle platforms for the fourth generation. Under Volkswagen's revised platform naming system, the "A4" platform became the PQ34 platform, and what would have been called the A5 platform was called the PQ35 platform.
The platform code is composed as follows:
A letter, P, indicating a passenger car platform
A letter indicating the configuration of the engine:
The A platform has been superseded by the MQB platform for new models, with the exception of a few models only sold in certain markets.
A1
The A1 platform debuted on the Mk1 Golf on its launch in 1974, and continued into the early 1990s, when the last remaining models using the platform - the Scirocco, Cabriolet, and Caddy - were discontinued.
The A2 platform debuted in 1983 on the Mk2 Golf, and lasted until 1998, when the original SEAT Toledo (the first Volkswagen-developed SEAT following the Spanish company's takeover by Volkswagen) was replaced.
The Volkswagen Passat B3 was based on a stretched A2 platform. The Volkswagen Corrado, while being an A2 platform car, uses some components from the A3 platform, notably the rear suspension assembly and some front suspension parts.
The smaller A03 platform, used in the Polo (6N) is based on the A3 platform as well, and shares many components.
SEAT Ibiza (6K) and derived models, uses components of both A3 and A03 platforms.
PQ34 (A4)
The A4 platform (PQ34 under the revised scheme) debuted on the Audi A3 in 1996 and went on to be used for many different models over the next two decades.
The PQ35 platform was designed to be more modular than previous A platforms. For the first time, a fully independent suspension was used in the rear of all A platform vehicles. The PQ46 platform is a variant derived from this platform primarily intended for larger vehicles, such as mid-size cars and crossovers. A common misconception is that the PQ46 based sixth and seventh generations of the Passat, are based on the PL46 (B6) and B7 platforms. However, this transverse engine Passat has little in common with the longitudinal engine "B6" and "B7" Audi A4.
