I used a home equity line-of-credit on our recent purchase ('95 E420), and it's the best way to buy a car as far as I'm concerned. I first tried to buy a car out of state and was thwarted by my local bank's auto loan program. When you get the equity check, the bank doesn't care what you buy with it since theyhave your house as collateral, and your interest (as John mentioned), is usually considerably lower.
Payments are also less if you need them to be (15 year loan in my case), but definitely DON'T wait that long!
Overall, you're using an appreciating asset to pay for one that depreciates - a much more effcient manner imho. Plus, you pay for the car in cash an get the title, which is kinda nice.
look into this option if you happen to own a home.
Regards,
- Ryan