You've been on vacation for the last two weeks and you don't have a care in the world. You've been driving around in a sweet rental car and you're just returning it to hop on a plane to your next destination. You drop it off in the lot and go into the office so they can give it a final once-over.

A mechanic walks past the office and give you an accusatory look. You look back, surprised and confused.

He calls you over and asks you to start the car. When you try to start the car--which you've been doing every day for the past two weeks--it doesn't work. The mechanic takes you in and they draft up your bill--with hefty charges for the "engine troubles" you caused. You insist you didn't do anything but they aren't relenting. Little did you know, the mechanic flooded the carburetor on purpose while you were waiting inside. The fees they're charging are way beyond what it would cost to fix it.

How to avoid: the scam is usually pulled on people who are not mechanically inclined. Simply put, they saw you coming a mile away. Tell them you've heard of the scam and threaten to call a lawyer. If they're smart, you'll be on your way in no time.