affective driving?

so here's an idea to make the roads safer (well, ok, maybe not safer, but at least
less unpleasant)

reading the very excellent book "Traffic" by Tom Vanderbilt (subtitle:
Why We Drive the Way We Do (and What it Says About Us, says it all)
which points out that cars "dumb us down" in that the bandwidth between people is reduced to hand signals and horn hooting....and this often leads to road rage etc etc

so why not put a webcam on the satnav computer and then connect it to a display on the front, back and sides of the car - and show other drivers of other cars nearby the actual mood of "this" driver?

this may sound hard, but Peter Robinson's gang in the Computer lab in cambridge have made great leaps at building mind reading machines already - nice
bbc article about it!