Well you could share direction you want to go, just be strict on no time frame.
I think most people are already expecting SG to join the 4K bandwagon too, and probably also the intermediate resolution cameras too.
No matter what it will be, i personally feel the remote camera are the way to go, no matter which resolution, it is simply better for stealth reasons, and i also feel it could be better for parking mode, and overall bitrate as you can pretty much do with the main unit as you please as its just a box the user have to stick somewhere.
So as long as its not the size of a shoe box it will be fine,,,,,,, helll i would put a main box that large on a super dashcam in the trunk of my car no problem.