I am vaugely inclined to agree, but wanted a deeper argument... And I tried to express that and came up blank. Plenty of places of work have an expectation that

I am vaugely inclined to agree, but wanted a deeper argument... And I tried to express that and came up blank. Plenty of places of work have an expectation that the customer can come and go or simply stay while you work on their property - any home repairs, of course, but even cell phone repair shops will typically do it in front of you. Why not mechanics? There are strict laws already around what a mechanic does have to show you - you are able to request that they give you back any parts they replaced, for example. I don't see the issue if with a dashcam that's set to record while driving. Their tests seem reasonable things for you to observe. I was initially with you, but on thought, why? This is worth arguing.