I brought my 16-year-old Toyota Camry in here for them to look into sputtering and slow idle on start-up. I left it there all day. When I came back to get it at the end of the day, they said they couldn't find anything wrong. (They hadn't checked for carbon build-up on the idle control, which is one of the first things a good mechanic would check given those symptoms.) A few weeks later, I brought it back again. I arrived right when they opened, and I told them they might want to check the idle control, since that had needed to be cleaned a few years earlier. I got no call from them all day. Well after their posted closing time, I called and asked for a status update. They told me that it would be ready in 30 minutes. I got there and found they had replaced the idle control valve and wanted $560 for the job. I told them that this was quite expensive and I asked why they hadn't called me to give an estimate or to get my approval on the price. They replied unapologetically, "We thought that's what you wanted. We can put the old one back in if you want." I asked whether they had bothered trying to clean the idle control valve first, which would have been much less expensive and probably would have solved the problem as it did years earlier. They replied that they hadn't tried that.
If you go to this place, ask them to call you with an estimate before they do the work. Though their service in my case may not have been intentionally deceptive, I felt it was sloppy customer service.