NFSUnlimited.net

This one's easy. Once you unlock a mod, it applies to ALL the cars in the game. That way you don't have to race the same race over and over and over to get mods whenever you switch cars. Otherwise, they need to have a garage where you use your credits to purchase the mods.

Thanks for the tip on the Panamera. Ariel Atom was killing me with the crash 5 times a lap nonsense.