Repossession: Private Repossession

My question involves a consumer law issue in the State of: Florida
To simplify a complicated story.... My sister and her boyfriend........
Borrower (my sister) has late payment bad credit history
Co borrower (her boyfriend now ex boyfriend) (NOT co signer) puts up cash on a loan to help borrower's credit instead of putting up the vehicle per the bank.
Co borrower is legal lienholder.

Payment is made but late, last day of grace period. My sister never makes anymore payments because she lost her job.

Her ex boyfriend hired a company to get the car back and put the car in his name since she can't pay it.

Is he able to sell the car? The tag office transferred the car into his name since he paid the car off. This is weird because it's not a bank that took the car back. This was the other borrower on the loan.

I know she didn't make the payments because she lost her job but if she can borrow the money from another friend, does she have a right to buy it back? Or is there a law that makes him sell it back to her?

All I can find is bank lienholder statues.

Repossession: Private Repossession