Oddly enough quite a while back I was driving a tug boat around underneath the Algonquin Bridge trying to parody a scene from Peter Benchley's The Beast
which led to me getting the tug boat onto the small beach by the gutted building where Corner Kids
takes place in TBOGT. Anyway everything was running fine until the tug boat ran aground on the beach, and suddenly everything began to lag horribly. I tried to drive away from the area so the boat would disappear but driving became impossible to do. I had to fire rocket after grenade after explosive shotgun rounds after hitting the boat with various cars just to push it back into the water, and so after successfully getting the now destroyed tug boat back into the water the lag finally ended and the game returned to normal.
That scared the hell out of me because I thought it was a problem with my PS3, not with the game itself.