Obtaining an auto loan with bad, or challenged credit is one of the least difficult things to do with bad credit. The reason for this is that all car salesmen are motivated sellers and there are a lot of auto lots that will sell an auto to just about anyone who walks onto their lot.
The mark up on used autos is substantial, so a car lot can have a deal go bad and still make money if enough payments are made on the car. If you have bad credit, it is best if you find an auto lot that carries their own paper, meaning that they finance their own car loans.
In this case, how much money you put down as a down payment is really the only thing that they care about. These types of car lots will always have an auto that they will sell you. You are going to have to come up with some type of down payment for the auto and at a auto lot that carries their own paper they will often time horse trade when it comes to the down payment.
Investment grade art work such as limited edition prints or antique coins or guns are just about anything of real value will often times work for this. Make an offer and see if it floats and try hard to bargain with them. If you have a new car on your mind, then you are going to most likely going to have to come up with a decent cash down payment and a cosigner to buy the auto.
A girlfriend or boyfriend or a sympathetic relative is who works best for this most of the time. If you can't find anyone to do this then it still can be done, but you are going to have to come up with a moresubstantial down payment and accept a much larger interest rate on the car loan.