Pontiac Repair: Pontiac Aztec, private buyer, sister in law

Question
Hi,
My sister in law recently purchased a Pontiac Aztec from a private buyer. She foolishly did not have the vehicle checked out first and simply bought it outright. She started having problems and her son in law checked it, telling her it was the clutch converter. She took it to an auto repair place and they told her it would be $700 to repair it. She agreed to pay them the money for the repair.
When she went to pick it up, they told her that it was not the converter but her transmission and that they had taken it to another shop to have the repair done. The cost: $2500! She told them she did not have that much money and they told her that until she paid them she could not take her car. She never authorized another shop to work on her car and she did not get a call from them saying the transmission was bad. They told her that she could make payments but she cannot afford the cost at all! Does she have any recourse at all to get her vehicle back? It's my understanding they cannot charge her if she was unaware of the repair. I suggested she tell them to put everything back the way they got it and go get her car! What should she do?
Thanks so much for a quick response!!!

Answer
Hi there:

I'm not too sure I can really help you on this but I'll try. If a repair shop performed work on a car with out the owners consent then the repair shop should be on the hook for the repair that was unauthorized. The shop should have documentation as to when the authorization was made from the customer and the time and who they talked to .If they do not have that then they are on the hook. IF the repair was authorized and they have documentation as to the OK for the repair then the customer is on the hook for the repair and depending on what state you live in the repair shop has all the right in the world to hold the car there until payment It's called a repair lean I believe. I'm not a lawyer but basically that is how it works.  Hope that helps you out.
Basically it comes down to a he said she said but if the repair shop did a their job correctly and documented an authorization or not is what it comes down to as to who is responsible.

Good luck:-)