In other countries, and perhaps here now, people get a discount on their insurance for logging their driving.
Right, so insurance companies can monitor your driving habits, and everything you do and everywhere you go is conveniently logged should the government ever wish to subpoena the recording data.
Yep. I didn't say it was a good idea, or that I'd do it. Only that it happens a lot and it's easy to do.
To be honest, though, the government won't have any trouble piecing together your driving history nowadays, not to mention your cell. You're certainly making it easier for them, but not really providing them with anything they can't ascertain anyway. Moreover, there's no reason why you couldn't encrypt everything since it's android. I looked into getting an android box for my car, they do a ton of nifty shit, and I would have just left it isolated from cell networks and encrypted its data.