Knowledgeable, friendly and with useful mailed coupons for existing customers (not just the teaser first service deal!) I've limped in with my old truck and had them give me a quick driveway diagnosis even when they're swamped, that alone would have made me a customer. No matter where you go a good mechanic is not cheap, but knowing they're going to be honest and work with you on keeping your vehicle running safely keeps me coming back.