Listen to what other drivers are listening to and/or let
them listen to what you are tuned to.
An occupant of a vehicle in motion can push a button on
their radio and share their AM/FM tuner
with other motorist via a short range wi-fi network.
It would transmit, and receive, a signal
that would
identify what radio frequency you are tuned to and allow
auto scanning of other users .
It should also have automatic and manual volume options
to afford more flexibility to the effect.
Actual audio and video, not protected by copyright laws,
could be legally shared also, but for now I'll stick to
the radio function.
When a motorist turns this on it would automatically look
for a
signal, and lock your radio into the
same channel as the nearest MESS motorist.
You could opt to stay on 360 degree search mode, limit
directional scan or block selected users.
You could set it to receive only, transmit only, or receive
and transmit.
In full mode (default) a chain of drivers could be locked
on
to each other and also see how many were in the group.
It could be promoted with
billboards that display readings from the most recent
passers-by and any user could change that info if they
choose.
-I'm sure a boatload of attorneys would try to all get on
board and it'll be a few years down the road.
*No, I don't think it should ever be mandatory. ;-)