What happens if you don't finish paying off a car in TN?

The car is eventually taken away, if we assume it has a lien on it. The cost of processing the legal work, the cost of repossession and interest will continue to be accumulated. The car will be sold to pay for these expenses and the rest of the money will still be owed, Typically the loan company will take you to court and receive a judgment for this debt. (These costs will also be added to your overall debt). The next time you have a job, a garnishment will be placed on your salary.

If there is any way to pay the debt, pay it before they take the car. You will be MUCH further ahead.