car pranks

[JARVIS518]

since april fools day my GM, the company accountant and one other manager have been going back and forth doing car pranks to each other and using me to help them and being that my last day at work is friday before i move back to NY i want to get all three of them.

so far we have done
+post its all over the car
+a life sized cardboard cut out seat belted into the passenger seat
+the head of the cardboard cut out taped to the front of the car
+moved cars to different places of the parking lot
+Vaseline in the door handle
+ tied cans to the bumper of car

i got a few ideas i was thinking
+put a for sale sign on the car with super low price
+fill car with baloons
+saran wrap total car

anyone have any better ideas

oh and because i am moving i dont want to spend a ton of money maybe $15
and obviously i dont want todo any damage to the cars