6 years of course.

1. You will pay less interst in total to the bank.

2. Many ppl will get itchy to change car after 5 years. With a 6 year loan, at 6 years, you can sell the car, n get the whole resell value, which you can use as an additional big down-payment for your next car. With 9 year loan, if you sell at year 6, you will get very little or even have to pay the bank on top of down-payment for the new car. The cycle of high debt continues.