Not every mechanic is as honest as our auto bodyshop in Seattle. Indeed, mechanics have a certain reputation for padding your bill. Unscrupulous mechanics are in a minority, of course, but they’re still something you want to keep an eye out for, particularly if you are either elderly or a woman.
Though it can be hard to measure such things, evidence has indicated that mechanics are more likely to overcharge women and the elderly. To defend yourself against this, there are several measures you can take. First and foremost, it pays to send the message that you are at least somewhat auto-savvy; do a little research on automotive fundamentals, and try to diagnose your own problem before you go into the shop. If you are able to discuss your repair needs intelligently and knowledgeably, your mechanic is more likely to see you as a peer and less likely to think they could get away with dishonest behavior.
Secondly, if you have the luxury, try getting two written estimates for parts and labor. Make it clear that you have another option available; when businesses need to compete for your money, you come out on top.