I think it's a great idea.
I always thought businesses that have customers in waiting should have secondary services to soak a few extra bucks off of them and to make their time less wasted. When I was in League City they built a Carwash and Grill. The idea was to eat steak and drink while you were getting a car wash, what I considered genius, but they never actually opened the grill while I still lived there, just the bar. So drive there, get drunk drive home. I had an issue with this, but went there anyways for one beer and then soda.
I always thought tire shops and what have you should have at minimum WiFi in the lobby. Most don't and usually have a TV pinned on something horrible. I think mixing up barber shops with lube and tire shops would be a great idea
If I were opening up a coffee shop (which I've considered) I would absolutely target spaces next door to tire, lube, brake, carwash, and any other place I could think of that would have people pinned in place without their vehicles. I tend to walk somewhere to eat when waiting for anything like that and will pick a place that has something within a reasonable/safe walking distance.