i know motor sport wont be included from the start but how about this a racing team gets in touch with you about you designing a race version of a current model (like a lot of le man touring car and rally teams do ) you keep the rights to the car and could make a road version of the racing car (like the Porsche 911 gt3 rs) say instead of a family saloon you get a racing light powerful sports car version of the saloon
if the team that bought the car won a race or championship it could also significantly increase you brand prestige therefore sales would increase .
also the teams could vary from local , regional , national , continental and worldwide with rally , endurance and sports car 40 lap race type races like the ginetta cup . even maybe a race for your brand once a year held in your honour.
my last thing is concourse events with judges voting on car appearance speed ect.