We buy a car for $30,000. They charge us 4% annual interest. We pay the loan off quarterly. We want to know the effective annual ROR and the quarterly amount to pay off the loan in 6 years. Furthermore, if we had enough after 2 years, how much do we need to give the lender to amortize? If we gave the lender $4,000 in addition to our regular amount after 3 years, How many more payments would we need to give?