A friend of my dad had a shop like that and he was a brilliant mechanic and one of the nicest people you could meet.
He took a job as an advisor for some construction equipment builder. He is called on when the builders and engineers can’t figure out the problems of the equipment they created.
I agree about asking friends and neighbors (or these days, yelp recommendations). We’ve got a great mechanic. When we moved to this town about 15 years ago, we went to a mechanic’s shop simply because we had received a coupon in the mail. They seemed fine. A couple of months later, when I was back and sitting in the waiting room, the mechanic came in and told another customer that she didn’t need new brakes, that her brakes had just gotten muddy, that he had cleaned them off and there was no charge. We’ve been going there ever since. Recently our air conditioner went out and we took the car in. We said something in the air conditioner had failed about a year ago (it was a $1000 job - about half part, half labor). The mechanic checked and the part was still under warranty. We figured we’d get the part replaced but would be paying the labor. He charged us no labor. (The following week we took two vehicles in for tune ups so he’d make some money off of us.)