He could have used the car - assuming he owns it - to borrow from the bank.
Probably could have gotten a few hundred thousand (against the car) if he wanted that much.........and at a relatively reasonable rate, too.
Then, just give the loan shark back the original 13,000 baht to settle the debt.
And then pay the bank back to get the carbook back over a number of years, at a few thousand baht per month.
He'd still have a few hundred grand in his pocket from the car refinancing, so he wouldn't have to worry too much about missing payments and losing the car.