Should you trust your auto repair garage?

To answer this question, economist Henry Schneider took his used Subaru to 40 garages, loosening the battery cable and draining some coolant before each visit. He even wrote himself a script and memorized it, to make sure he was telling every garage the same thing. “We bought the car recently, and we should have had it looked at before we bought it, but we didn’t,” he would say. “It hasn’t started a few times. Can you check that out?” He also asked for a thorough inspection.

At only 27 of the 40 garages did mechanics tell Mr. Schneider that he had a disconnected battery cable, the very problem to which he had pointed them by saying his car didn’t always start. Only 11 mentioned the low coolant, a problem that can ruin a car’s engine. Ten of the garages, meanwhile, recommended costly repairs that were plainly unnecessary, like replacing the starter motor or the battery. (Tellingly, his results were in line with what the Automobile Protection Association found when it performed its experiments in Canada.)

Note that this is similar to the experiments run by 60 Minutes that exposed a similar problem at Sears Automotive.