Payment arrangements after voluntary repo?

I know I am responsible for the balance remaining after auction but can I set-up payment arrangements? Its only 1 income in our household $1600 monthly w/ 6 dependents. I will agree to pay $50 monthly. Although, this would never pay it off I would give extra after taxes but only want to agree to $50 a month to ensure it does not put us in the rear. Would they accept this or do they want payment in full?