Anyone here play Forza 4? Because I'm having trouble doing the prototype speedway showdown (4th group, bottom of the 4th row on the event list board). I know to make an X-class car you need to take an R1 car and remove the restrictor plates, and I've done that with 3 cars (#2 Audi Sport NA R8, #16 Dyson Racing Mazda, and the #11 Matmut-Oreca Peugeot) and it says X-class with a rating of 999, but it still won't let me do the race. Do I need to buy and use a different car? Do I need XBox Live (which I don't have yet)? Is it some kind of glitch? Any help would be appreciated.