Yeah, I always thought you could flip them too, but, nope. go to Smokey Moutain Rally race with a really light car, like the Escudo and go like 200 of those bumps and you go flying.
You know the trick where you put the downforce on the rear of the escudo to max, the front to min and drive down a straight (Test course). I did this and went into the scenery (wall) and the PS2 just jammed. The screen went mental
oh yeah... ok,.... thw wheelie trick. You can smash your can and fly into the air,.... with the 'perception' that your flipping,... but the car is actually 'spinning' and 'teetering',. not flipping.