Take Alaska Fish Fertilizer -- one of the most vile smelling substance on the planet and pour it into the air intake on a car. The smell permiates every bit of the car. It is so bad that the car is rendered undriveable.

You can also pour this into just about any air intake for a church, a school or an office. I'm not going to tell you to look for the hard to find original formula that is not deodorized, because you're never going to pull this prank in the first place.