Why didn't you get notification from the CC company that a dispute was opened, the law requires them to contact you in an effort to resolve the dispute.
You are also entitled to attempt to resolve the problems with the merchandize that was purchased e.g. make repairs.
Buyer can not keep the car if it is not paid for under any circumstances. It could rise to the level of theft just as if someone buys merchandize with a check and then stops payment and doesn't return it.
Look up the CC laws and regulations on disputes in PA. There are time limits to resolving disputes.
Here is the visa handbook on chargeback. Start reading on page 49. I would think that all CC companies have similar policies.