Dash man
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
I do almost all my own car and home repair so I don't do this often but there is occasionally the need. I always use a known person with a good rep and it's usually a one or two person small business. In my experience they will do a far better job than some of the big companies. They have their word of mouth reputation to rely on for new business. Last week I had a slow air leak on a custom race-tuned suspension and the repair is a bit above my skill level. It turned out to be simple fix, done in my garage and was charged $100. If I took this to one of the big shops it would have been a thousand. Did the guy claim the $100 as income? Don't know and not my problem. He's the one running the business.
As for online bank use only; i'll probably have stick with at least one brick an mortar establishment.
It's your choice who you do business with. Is he insured? If he'd been hurt in your garage who would pay his medical bills? If he doesn't pay his payroll and income taxes, others pick up the bills later on. Not your problem? We'll see.