I’m with you there struggling to trust dealers, I am on pins when I leave my car there and to be honest I think they feel the same.
I can rest easy leaving my car with the independent, totally trust them and know that they wouldn’t do anything I wouldn’t. My worst nightmare with dealers is that they take the car on a test drive and boot it when the car is cold, seen it too many times. Quality of the work is hit and miss depending on whether you have a good dealer or not. I struggle to find technicians who genuinely seem interested in the cars, beyond it being a job.
I’ve had the dashcam unplug policy argument before, been told it is because there is secret development in the workshops that customers aren’t to see. No there are technicians f’ing and blinding that they don’t want to see, that’s the only thing being developed haha. Once they unplugged it, but when mine went in next and I kept quiet they left it plugged in. When I reviewed the footage after they changed my exhaust for the revised ‘rattle free’ system, keep in mind the issue is when idling on a cold start. He started the car, it was on a cold start and he revved the nuts off of it for about 30 seconds up to the 4000rpm limit and said “seems ok”, making it pop and bang in the workshop. That really p’d me off, I’d never dream of doing that myself.. but I kept quiet because I felt that was somewhat minor and I’d rather it be plugged in to see if they did anything worse down the line.
My latest dealer, have left the camera plugged in at all times but say they test drive my car when it never leaves the forecourt... I think they’re too scared to.