The median age of cars and light trucks in the US is around 9 years. That means it will take 9 years for this system to reach 50% penetration, once it becomes available at all, which is probably 3 years away at least. At the rate things are progressing, do you really think autonomy won't be a solved problem, or nearly so, in a dozen years?
I can see the attraction of this system from a strictly engineering point of view -- it would be nice not to be limited by line of sight. But how many collisions between vehicles have you ever heard of where the drivers literally couldn't see each other until too late? I think these are pretty rare. Seems like occlusion is more of a problem when pedestrians or cyclists are involved, as they sometimes pop out unwisely from behind parked vehicles; but they're not going to be wearing transmitters. Also, radar provides some ability to see occluded vehicles; transmitters are not even the only solution to that problem.
So, given the threat to privacy this system would represent, I don't see that the benefits approach the costs.
