HARRISBURG, Pa. (WHTM)– The internet has made it easier than ever to buy and sell things, that includes cars, and if you’re in the market for a used one you’ll want to be sure you don’t shell out a lot of money for a vehicle with hidden problems.

“I don’t know how they can sleep at night doing that,” Good Karma Garage President Jeff Case said.

Over the past six months, Case says several people have come into his garage in Harrisburg.

All of them had recently bought used cars and none of them came from dealerships. And Case says all of those vehicles had problems the customers were never told about during the sale.

“One was extremely annoying, the check engine light came on as they were driving home from buying the car,” Case said.

Annoying, at best but hidden issues can be very expensive. Police say the best way to prevent it from happening to you is to follow some classic advice.

“If it’s too good to be true, it probably is. So obviously just be aware of the dealership or person you’re buying it from,” Harrisbrug Police Lieutenant Kyle Gautsch said.

“The best thing to do would be to have somebody go with you that knows about cars, that can look at it,” Case said.

If that’s not possible then insist that the car be checked out by a trusted mechanic, or, you can buy one of these, an automotive code reader, which is the same device mechanics use to check for problems under the hood.

“And it will tell you what the status of the emissions codes are, that’s the most important thing cause that’s how you can tell if they cleared the codes or not,” Case said. “What you want to do is plug this in and make sure all of these are green.”

A spokesperson from the state Attorney General’s office says if you think you got a raw deal on a used car, file a complaint with the AG.

And they really want to emphasize that before any sale, consumers do have the right to have the vehicle inspected at the mechanic of your choice before you agree to buy it.