Rollover is a hidden bronze-level PSN trophy available in Gran Turismo 5.
In order to win this trophy, a player must roll their car so as to land on its roof. While this can be done at almost any circuit, it is easiest done at the final corner of Trial Mountain Circuit. To qualify, the car must roll and remain on its roof until the car 'respawns' on its wheels; simply rolling back onto its wheels is not good enough.
Note that, due to a difference in the physics engine, it is impossible to roll the car in an online race, though this is impossible now due to the online services being offline.