instead of a personal unsecured loan, your son will be better off getting an auto loan. his chances are going to be much higher, and the APR is probably going to be lower, compared to an unsecured personal loan, only because an auto loan is secured with the car itself being collateral.
Why not pay less downpayment, get an auto loan, and then use the original amount of money he meant to include as downpayment to pay for his credit card? Basically the same thing in the end, except he'll have an auto loan instead of a personal loan.
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