Bad credit car loans per my knowledge can be viable tools to shop out a car as well as build credit score. However, I will not rush to get bad credit loans if I already have a car that I can use. Rather, I would try to repay or consolidate by existing loans.
These loans can be used if you do not have a car at all or can best work if you are planning to lease some cars for business purposes. With these loans being subprime loans they are highly priced in rates. Unless I am really in dire need for a car I would not opt this route. There are several other options to rebuild credibility though this too would help.
If I am worked out beyond limits with multiple loans and credit collection calls I would rather prefer to put off this loan for sometime, pay my other bills on time, create a credit score by that way, and then approach the bad credit car loans lender so that I can get some discount on the rates of interest.
My opinion is that these loans are gifts from heaven for people with bad credit scores.