When the tour of the park first starts and Dr. Grant jumps out the car door, he leaves the door open. But then when Dr. Sadler jumps out of the jeep both doors mysteriously slam shut. There's no way that she could have slammed both doors simultaneously while the jeep was moving and she was trying to get her balance from jumping out of the jeep.
Also Dr. Malcolm could not have closed them because while he says, "Now here I am by myself, ...uh.. talking to myself. That's chaos." You can hear the doors shut.
Get your facts straight, the cars that they are in are not Jeeps, they are FORD EXPLORERS, if you look relly close when the T-Rex is smashing the car into the mud it says EXPLORER, im tired of people calling them jeeps.