Question 1

Should I take the longer term for the lower payment?

Accepted Answer

Look at the "cost of stretching" line. On a car, a longer term also means more months where you owe more than the vehicle is worth, which is the part that actually hurts if you need to sell.

Question 2

What about 0% dealer financing?

Accepted Answer

Enter 0% and compare the total against the cash price minus whatever rebate you forfeit by taking the financing. The rebate you give up is the real interest rate in disguise.