Auto Finance Payment Calculator

Question: Which is better, a $2,000 rebate with a standard auto interest rate or 0.9 % finance without the rebate?
I haven't found a good website to find an automobile payment calculator to break this down for me over the entire life of the loan. If you can show me the site or crunch the numbers, I'd appreciate it. Consider a car at $20,000 for five years at 0.9% versus a car at $18,000 for five years at 6%. Thanks!
Answer: It's close, but you will save $7 a month by taking the 0.9% financing instead of the cash back.
I think this is the calculator you have been searching for.
Just click on the 2nd tab, which says "Decision, Low APR vs.Cash Back"
Auto Payment Calculator - Amortization Schedule