Check out www.Peoplefirst.com. I just refinanced my Suburban, going from 11% to 7.09%, which cut my payment by about $50 per month. It was so painless it was hard to believe. You apply, they check you out, and if they approve you THEN you send them some minor documentation. I applied late at night, and around noon the next day I was approved.
A check arrives in the mail in a few days, you take it to payoff the other loan, send back some paperwork, and you are done. Obviously good credit and auto-deduct from your account get the best rates. So far I have not found any catches, but I will keep my eye out for any drawbacks. Apparently the company is well thought of, so much so that a large bank just accuired them in a $150 million buyout.
