i tell you ive played that game heaps and ive experienced a number of them. one of the less noticable things is if your car is going to fast when it hits a barrier and crashes it can go right through it.
i drive the bugatti. and there have been times were if crashed on the outskirts of a road or on a highway and have went into and occassionally through it. although i think yo have to be going pretty fast like near 200. there was a problem with vehicles being spawned when jacking them as the vechile i changed from got placed on top of what i had changed to. however that was before the original update was given out. so that glitch has probabkly been fixed as ive never experienced it since.
i didn't intend on finding all of these glitches. but i guess it was either luck or merely me playing the game to its full extend that allowed me to find these glitches. (trying to sound not to ego driven/arrogant there)