I agree with VR statement ( never owned a TW system )
This is somewhat a downside of the system, that if the "kickoff" come from behind you do loose the actual impact and a few seconds after that as the system first have to boot before it can record.
The kickstarter system i am on board with, and might get ( it is over a year late now )
It have been upgraded to also have radar in the rear camera + it have a additional chip in it, so you can access it remote even if it is in deep sleep, something the TW and BV cameras with radar do not allow as far as i understand.
Though it is also no big deal CUZ who would log into the camera when there have been no notification, so really once the "new toy" period have set in i doubt many would actually use that feature in that system.
Also i am unsure if this 2 radar go for the actual production cameras or it is something they have thrown on top for us supporters that have had to endure extraordinary long even for a crowd funding thing.