My mental wanderings had me realize this would be an ideal tool for LE, specificly HP and traffic.
The only thing I could imagine that would increase its workability would be an instant cloud upload or off site monitoring.
The idea of a police drone circling a traffic stop taking live video could be a pretty strong deterant against violence.

https://www.lily.camera

Just might work if they can follow a high speed pursuit at a hundred MPH.
But then again, everyone who is stopped should know that they are on dash cam and even that doesn't stop them from acting violently at times.

Yes the 1;1000 traffic stops that result in a high speed pursuit would probably not be recorded. The other 999 however would.
I think that visually seeing a drone circle your car and getting pictures of your face and not blurry video of of the backside of a headrest is a benefit.
It would be ideal for accident reconstruction.
A very simple mount on the trunk lid that deployed the unit on command would be easy to create.

Might not happen tomorrow, but it's probably coming.

I think that's a pretty good idea, especially it the police don't have to operate it. It is a royal PITA to use and maintain recording equipment.