Get first place in the indicated race in the Manufacturer Club Series to unlock the corresponding car:

1967 Ferrari 330 P4: Club Ferrari
1995 Toyota VIS Racing MR2 Turbo T-bar: MR2 Cup
1999 Lamborghini Diablo GTR: Running of the Bulls
2000 Audi AWE S4 Tuning Silver Bullet S4: Audi Cup
2000 Dodge Hennessey Viper 800TT: Viper Performance Cup
2000 Nissan Top Secret D1-Spec S15: Nissan Racing Club
2002 Honda Mugen Integra Type-R: Integra Cup
2003 Volkswagen Golf R32: Volkswagen Driver's Club
2005 Chevrolet #99 Tiger Racing Corvette Z06: Corvette Touring Cup
2006 Porsche #82 Red Bull 911 GT3 Cup: Porsche Sports Car Club