While this is a tip I haven't tried yet -- but will -- I thought it's worth passing it along to the TipHero community. Apparently, you can save a lot of money by taking your car that needs repairs to a school that trains students on becoming auto mechanics. These students work on cars for free, and they have instructors overseeing them to make sure the work they do is of good quality.
MSN has an article about this, and they provide one example where someone said they saved $3400 by taking the car to a school instead of an auto repair shop. And, aside from the huge potential savings from doing this, you also might even get better service than a lot of the auto repair shops out there that are more focused on profits than figuring out to repair something correctly.