I heard that on a day when it has rained and a car is wet, if you put corn flakes on a car, when they dry they stick to it and ruin the paint. But that'* only something someone told me. It doesn't seem like it would work, but who knows.

someone told me that if you **** in his radiator his A/C will smell like that for a long time. Might want to get a container & then pour it in to avoid suspicion...

Somone told me that luch meat takes the paint off of cars.

I always wanted to try something with pancake batter.

I think glitter would work well too. You can buy a can of glitter and dump that stuff all over the seats and dash. If he sits on it or touches it he will never get it off his skin!

You ever tried to get glitter off your skin or clothing? It'* damn near impossible. And he will look like a fairy!

http://www.prankplace.com/bumper.htm would be funny as long as he doesn't notice it when he drives away, its only magnetic. Some glue would work wonders on that though . Also if its warm enough out putting oreo halfs white side down on his hood will make fun little pin stripes that are a pain to remove.

Crab claws.
Fishing line.
Screwdriver.

Tie crab claw to fishing line and drop it down behind the lightswitch in the engineers office.
This will produce a particularly funky stank in just a few days.
Be sure to fasten it to the screw for later retrieval to remove the evidence.