Alan grabs the steering wheel and turns it. Causing the wheels to turn and the jeep to plummet. Apparently, the T. rex is drunk, stoned or just hopping, because the footsteps come and go and follow absolutely no pattern whatsoever. When the T. rex blows Grant's hat off, you can see that the air is coming from just behind the dinosaur's head. Shawn Bailes tells me that Lex and Tim don't appear to hear the T-Rex roar at all until it's half way through the roar.
Federal law prohibits the driver's side mirror from being anything other than flat.
However, the goat cage, which it was parked next to, was at road level. Also, as the jeep falls, the headlights go off, and then on again, without any intervention. As Dennis falls down the waterfall by the crashed jeep, he leaves the winch cable with the jeep. He subsequently picks it up again, at the bottom of the waterfall. As he is running around trying to get the jeep's winch cable tied around the tree, we see the gas jeep in the background with all its lights on.