In response to WhatNowDoYouWant's comment:
210 deaths caused yearly by people backing up in vehicles without paying attention.
Solution: require ALL vehicles under 5 tons to have rear-facing video cameras by 2018.
Cost/benefit doesn't seem to make sense, plus, the people causing these deaths aren't paying attention. If they can't look behind them or even glance in their mirrors, why would they glance at a camera?
Plus, more manufacturers are already putting these in, due to demand from the consumers who actually do like to pay attention.
So how is this going to help with the people who do not like to pay attention?
Seems to me a better solution, if you are going to make another regulation and given cost/benefit analysis as well as your proposition that many people do not like to pay attention, is to require vehicles to have a sound systen notification.
Many cars already have this. When there is an object/person behind you when you are backing up, the audible beeps get louder and closer together. Even people who are careless are forced to hear these sounds. They are automatic versus looking into those sometimes rather small rear view cameras.
Of course you can have the camera as an option but I think the above is the better mandatory way to go.
Back-up sensors is the term I was looking for above..