While your victim is driving and you are the passenger adjust the side mirror. After awhile it will annoy the driver.

attach a fishing line with objects to the rear bumper of your victim's car. When he drive off, he will be dragging items along with him.

In the winter time, when its freezing outside...dip some cotton balls in water and place them all over your victim's car.

Mess around with a victim who has aleady wrote directions down. When he or she isn't looking change the directions to send them in the opposite direction.

Have some fun on your next road trip. When your passenger falls asleep and is leaning on the right front window. Try this, quickly jerk the car from right to left then back. Then watch your victim's head bounce back and forth against the window.

Place a fake company sign on the side of your victim's vehicle. Have the sign read something like: "Handy Auto Wash - The Best Hand Jobs in Town. Be creative use a company and slogan that would get alot of looks.

Know someone who supports PETA? or loves and helps protect the environment? or maybe the person is a homophobe. Well just place a bumper sticker on his or her ride that gives the opposite message such as "I love KFC chicken" (for PETA supporter) or a rainbow sticker that reads "Gay and Proud" or for the environmentalist, have it say something like "I favor oil fields over rain forests"

Pour some confetti in your victim's defrost vent and turn it on high. When you starts the car up the next day, it will be like New Year's Day all over again.

Place a blown up balloon under your victim's tire. When he starts the car up and drives off, he will hear a loud POP!! and think the tire just blew out!

When your victim isn't paying attention. Get his keys and move his car. If he parked out in the street next to the curb. Then just turn the car around so it is now parked the wrong way.

Shatter a glass bottle and pour it around your victim's car door and inside his car as well. Then roll his window down and run screaming, to tell him something happened to his car.

Pour some sugar around your victim's gas cap. Drop a couple handfulls on the ground below, or anywhere else you want to leave a trail. The person will think someone poured sugar down their gas tank. In actuality, nothing is wrong and no harm was done. The worst that can happen is the victim will get a tune up in result, and the car will run better than before.

Place an open tuna can under your victim's car seat. It will take him a few days to figure out exactly where the horrible smell is coming from.

If you know how to re-wire cars electrical systems, then this prank is for you...While your victim is away from his car re-wire it so the low beam headlights are swapped with the highbeam, or try making it so everytime he steps on the brakes the car horn will go off. Be creative!

Offer to wash your victim's car. But before doing so, go down to your local locksmith and buy a key that is similiar to his car key and snap it in half with pliers. Then replace his key with the fake key on his key ring. Tell him you are so sorry, but you accidentally snapped his key in half.