Diesel Bombers - Myth Busters Automotive

If a car's tailpipe is plugged with objects, the engine will be destroyed.
Busted
All of the objects used were shot out immediately after the engine started up.

If a bullet is shot through the fuel tank, it will explode.
Busted
The gas tank did not explode.

This was revisited in MythBusters Revisited. A car door can protect a person from bullets in a shoot-out.
Busted
The car door did not stop the bullets shot at it.

A car's engine will be destroyed when liquid drain clog remover is put into the tank.
Busted
The engine still ran.

A car's engine will be destroyed when bleach is put into the tank.
Plausible
The engine soon died out but wasn't ruined from the experience. The following morning, the inside of the gas tank was covered in rust.

A car's engine will be destroyed when sugar is put into the tank.
Busted
The engine ran even better than without the sugar.

Adding mothballs to the fuel tank increases the horsepower.
Plausible
The engine still started, but it soon started spluttering. When Jamie pressed the accelerator, the engine sounded more powerful.

Cola can be used as a substitute for radiator coolant.
Plausible The engine ran with cola in the radiator, but it may cause damage.

If a radiator is leaking, cracking an egg into the radiator will plug the holes.
Plausible
The engine was started after the contents of an egg were poured in, and the leak stopped.

A piece of metal can destroy an engine when it falls in the carburetor.
Busted
A penny dropped in could be heard rattling, but the engine still ran.

Bleach in the oil can destroy the engine.
Confirmed
The engine started but it soon started smoking, and very quickly overheated. The engine was so hot, that the undercarriage started burning and Adam fried an egg on the tailpipe. The engine was ultimately ruined.