How to Trash a Rental Car

Make it permanent. Anyone can throw a bunch of food wrappers into a rental car, but only the real pros can leave smells that the auto detailer will never be able to remove. Milk and fish oil are two favorites, especially if you're traveling in warm climates. Pour the liquids into the upholstery, making sure that you get them deep into the crevices between the cushions. Placing raw fish underneath the seats leaves a stench that take weeks to eliminate.

Drive like a crazy person. Seek out potholes and debris with a passion. If you're really diligent, you can throw off the alignment of the car for good.

Mess with the paint job. A ding in the door is an easy fix, as is a scratch in the paint job. So stick with spray paint. It's almost impossible to remove from the car, and usually requires a new paint job.

Break a taillight. It's a simple enough thing, and sets the rental car company back a few hundred bucks.

Mess with the electrical system. In most cars, the fuse box is located near the pedals. Start taking fuses out and switching them around. Eventually, you'll break something important.

Bring along a screwdriver. If you really want to trash a rental car, you must do a bit of surgery. Remove the air-conditioning vents and throw in a handful of pennies and nickels. They're almost impossible to retrieve and will provide future renters with a mind-numbing rattle that will drive them up the walls. Bonus points if you throw in some leftover fish.