> It's also not clear what the purpose of this line of argument is.

It completely dismantles your previous goalposts, which were planted firmly on GPS:

>> Not with the necessary precision. GPS doesn't work in tunnels or parking garages and can be wildly inaccurate in city centers with skyscrapers blocking line of sight, for instance.

(I guess we all have the freedom to be as flexible with our goalposts as we wish. I didn't come here for a tireless argument that is motivated by nothing but the desire to argue, though. Have a great day!)

My line of argument is "the head unit is responsible for not allowing video playback while in motion". Anything to do with detecting motion came after that.