Rustad started his motor sport career in karting before racing in the Norwegian Rallycross Championship, winning the so-called Supernasjonal title for six years in a row between 1987 and 1992. On 14 June 1992 he claimed overall victory in the Irish round of the European Rallycross Championship at Mondello Park, racing one of the two 650bhp strong Ford RS200Group B cars of his compatriot and mentor Martin Schanche.
In 1998 Rustad got a drive in the British Touring Car Championship. He drove a Renault Laguna for the DC Cook Motorsport team in the Michelin Independents Cup, despite getting some backing from the Renault works team. With five class wins throughout the seasons, he was crowned independent champion. A sixteenth place overall finish saw him one place ahead of works Peugeot driver Tim Harvey.
STCC
Since his drive in the BTCC, he has spent most of his career driving in the Swedish Touring Car Championship. He was champion in both the STCC and the Norwegian Touring Car Championship in 2000, driving a works Nissan Primera. After this he spent a couple of seasons racing in the European Touring Car Championship, before returning to Sweden in 2003 in an Opel Astra. After another rallycross year he returned to the STCC Opel Team in 2007. 2008 had him drive a works Volvo C30 powered by bio-ethanol for Polestar Racing. He went on to win the championship for the second time in 2009 for Polestar.
After his retirement from tarmac racing, Rustad took the decision to return full-time to rallycross in 2013, driving a Volvo S40 Mk1 in all the rounds of the Norwegian Rallycross Championship for SuperNational cars with an engine capacity of over 2000cc. He was also seen in the two Scandinavian rounds (Norway and Sweden) of the 2013 European Rallycross Championship, driving a rented Volvo C30 SuperCar. In 2014 he participated in six of the twelve rounds of the inaugural FIA World Rallycross Championship, again racing a Volvo C30 SuperCar, but with little success. However, while finishing 27th of the final WorldRX standings only his sixth place overall in the EuroRX series was a much better result. For 2015 he was entrusted by his sponsor with a competitive VW Polo Mk5 SuperCar of the Volkswagen Team Marklund Motorsport, which he used successfully to claim his first European Rallycross title. Of the five rounds counting towards the EuroRX series Rustad won three, beating his strongest competitor Jérôme Grosset-Janin from France to second place.
Racing record
Complete British Touring Car Championship results
(key) (Races in bold indicate pole position – 1 point awarded all races) (Races in italics indicate fastest lap) (* signifies that driver lead feature race for at least one lap – 1 point awarded)