Mechanic conversation

When you take your car to a mechanic to be fixed, if you reliably understand the problem, don't tell your Mechanic. Instead describe the symptoms and ask for advice on what to do. You can then compare your knowledge against his advice and proceed.

Otherwise, if you're wrong, the mechanic will attempt to fix a problem that wasn't there and charge you all the same.

Speeding to a stop

Accelerating to a red light is a waste of gas. If an upcoming light turns red, remove your foot from the gas pedal and coast the rest of the way, applying the brake when necessary.

Inside/outside AC settings

If there's frost on the outside of the windshield, blast the AC with heat. If there's condensation on the inside of the windshield, blast the AC with cold.

Post parallel parking

Before you get in your parallel-parked car, make a mental note of how much space lies between your car and the cars parked behind/in front of it. You'll feel more confident backing out/pulling forward.

Towing prevention

A tow truck cannot tow a car when someone's inside of it.

Best "insurance plan"

The best way to keep your car in working order is to consistently replace your cars oil. Running low on oil severely damages the engine.