Your chances of getting approved go up if you keep your price target in the comfort level of most banks -- somewhere between $7,000 and $12,000. At Auto Loan Central, you can see all kinds of car bargains in that price range.
If you need to estimate your payments, try the calculator at CarLoans.com.
For research on all the new car bargains out there, try Yahoo Autos or Cars.com.
In terms of niche loan sites, try the following links:
Really bad credit car loans
Car loans made easy
Poor credit car loans
Auto loan information
Auto loans made easy
TIPS AND ADVICE
Don't focus on your monthly payment, focus on the total price of the car. Any monthly payment can be made to fit if you stretch the loan out long enough -- and that can cost you money.