Originally Posted by AllanJ
Before starting off, inspect the car for damage no matter how slight. If this helps make sure you don't miss a spot, drum your fingers all the way along the sides of the car as you look. Inspect the inside, too, for cigarette burns, etc.
This is excellent advice. Turn the headlights on and make sure the blinkers are in order. Make sure the cigarette lighter is there; if it's missing, they might charge you for it even if you picked up the car with it already missing. In addition, turn on the engine to verify that you have a full tank or at least the needle is pointed directly at the F. If it is even slightly under, choose another car.
Make sure you don't sign up for the "convenience" of having them fill up the tank. Major ripoff.