The best way to avoid auto repair rip-offs is to be prepared. Knowing how your vehicle works and how to identify common car problems is a good beginning. It's also important to know how to select a good technician, the kinds of questions to ask, and your consumer rights. 
Contributed by: Federal Trade Commission
Last Reviewed: 07/17/2009

http://www.ftc.gov/bcp/edu/pubs/consumer/autos/aut13.shtm