Great idea Dave K!!!
Basically parking sensors, but ones that know it's a car not a barrier
. It would resolve lots of issues relating to visibility & the driver shifting his focus (camera or mirror).
Maybe people should think about getting rid of the mirrors completely (make it a rule that no-one has them)? Add in audible position sensors for REALLY close proximity (perhaps less than 1M).
More drivers use mirrors to defensively position their car than use them to avoid accidents!!!
No mirrors means that the guy behind KNOWS the guy in front doesn't know he is there, so drives accordingly. The guy in front cannot use his mirrors as a tool to help blocking and weaving and can only drive on his normal line.
A problem with lapped cars remains, but it wouldn't take a genius to work out codes of behaviour when you see blue flags. For example only the car(s) doing the lapping are allowed to overtake under a blue flag and if you are shown a blue flag you have to leave a car's width to the inside on the next corner.