Bad credit is more common in recent times than every before, due in large part to the recent economic downturn. While it can make things difficult for some period of time, drivers with recent credit issues can indeed be approved for auto financing, IF they work with a dealer and/or lender who is spefically set up to handle loans for those with challenged credit.
While every car dealer probably says that it can get anyone approved no matter their credit score, most of them are blowing smoke, and they are just trying to get people in the door (even if they can't approve half of them). If you go to a restaurant that boasts the "World's Best Apple Pie," you probably should go ahead and assume that they can't back that claim up.
However, a select number of dealerships across the United States and Canada are fully capable of handling poor credit consumers. This is accomplished by having relationships with particular finance companies who are lending to people with damaged credit. These lenders are choosy about what dealers they work with, and they generally only establish relationships with top-quality car dealers and some in house financing car dealers who have a strong reputation. This relationship between bad credit lenders and the car dealers is beneficial to everyone: The car dealer sells more cars, the finance company closes more loans, and the consumer is able to get a reliable car despite having had credit problems in the past.