I keep my keys on a carabiner so it's easy to take off the car key.I rarely go to a shop unless it is for a state inspection or something I don't have the time to do due a business obligation. If I do go to a shop anything of value gets taken out, I make a note of the miles on the vehicle and make sure they only have the keys to the vehicle. The house key comes off the key ring.
Usually for inspections I just take a half day off from work and wait. Actually for most repairs I will do that. Easier than planning rides to/from the shop. Occasionally I'll drop off the night before, pick up the following night, but still, it's planning rides.