Things that could conceivably cause you to fail your driving test

insisting on your typical "naked from the waist down" driving during the test
mowing over a pack of cub scouts
screaming "whooooaaaaaa horsey!" at the top of your lungs every time you apply the brakes
eating nothing but beans for three straight days before the test
playing the "punch buggy" game with your driving instructor
95 in a school zone
constantly making the "vvvrrrrrooooooooom" sound for the duration of the test
getting out for a chinese fire drill at the every stop light
casually putting your arm around the instructor at stop signs
your first stop - McDonald's drive through for a happy meal
dozing off more than a couple of times