[blackdog]

And by the way, a teaspoon of baking soda in a battery cell will cause the entire contents of the cell to immediately evacuate the battery casing like old faithful.

For automobile pranks, I prefer the ping pong ball with two small holes in the gas tank. When the car sits still, it sinks and settles on the fuel line opening, blocking the flow. After two days, it's disolved from the fuel. Right about the time the mechanic will drop the tank. Every time a towtruck moves the car, the ball rolls off the opening from being tilted and the car will start and drive. Once it's parked for an hour again, it dies.

[asgardshill]

Yes, much like "Old Faithful" under your hood. A lot of white stuff, easily overlooked by a non mechanically-minded lib (except when it comes time to start the car again).

And the ping pong ball is an oldie-but-goody as well. I'm a proud graduate of the "Write Creative Messages in Brake Fluid on the Vehicle's Paint Job" school.

[Balding_Eagle]

Have you even seen the inside of a gas tank since 1970? I'd guess not. Today the tanks have pumps inside them with multiple inlets, You're wasting money on ping pong balls.

[Chad Fairbanks]

Ya know, I hear tell that 12-15 moth balls in a gas tank really increases the octane level... I also hear that it makes it really hard to shut the engine off once it's been started.

[Old Professer]

That trick might work on an old VW Beetle; all cars today have in-tank pumps that pull from all sides.