I bought it today, installed the "install" disc, then as soon as it was done (not even 30 minutes) I took the disc out when it said and entered the play one. It was framey during the cutscenes, and when I took a hard turn with either player or vehicle. I quit it, deleted the install which was in four parts for some odd reason, and installed it again. This time, instead of taking out the disc when it said I dashboarded it and then entered the play disc, which is what my friends did and it's fine for them.
Now that I've unistalled and reloaded, it all seems okay, apart from when I crash (or stop the car) and start the car back up after crashing? It just seems like the Xbox can't handle it doing it, and it all slows down which just doesn't look right. Anyone else? Any fixes?