Due to divorce issues, my credit rating has suffered substantially. I'm currently in the process of rebuilding but I need some advise.

I just bought a "new" used car and got an abysmal 15% interest rate. next week I'm selling my mom's house that i inherited and will be able to pay off the car in full but I need to know if it's better on my credit to pay it in full, to pay much larger monthly payments (2k-2500) or to pay the normal monthly? The interest rate is so high that I know if I pay it the regular monthly payment for the full term I'll be paying MUCH more than i'd like in interest so I need a happy medium between bettering my credit and not paying the full value of the interest over the term of the loan.