Keep an eye out in parking lots for piles of broken glass left over from a prior car break-in. Or you can take a trip to the local junk yard and look for a vehicle which already has a shattered windshield. Carefully collect the glass shards.
Set the stage by sprinkling the glass pieces around the area outside of the car. Roll down the car window of the person you intend to play a prank on so that no part of the window is showing. Conspicuously place a baseball in the vehicle seat along with some of the glass shards.
Laugh cruelly when your friend gets to their car and thinks their window has been shattered.
Idea #2 has a really easy setup and works well on anyone who owns a truck or jeep. You’ll enjoy this most if the person you play the prank on works in your office and you get to hear their phone ring during the day.
Purchase a standard “For Sale” sign from your closest retail store.
Write your friend’s phone number in large letters for the contact information. For asking price put something really low like $300 dollars.
Place the “For Sale” sign directly in the back window of the vehicle, behind the driver seat where its view will be blocked to the driver by the seat headrest.
Count how many offers your friend gets from strangers who want to purchase their vehicle until they investigate their car and see the sign. Award yourself additional points if the phone calls continue after the sign has been removed.