Gibson wrote about something like this in his last novel [Pattern Recognition] …

“Roadcasting is collaborative, mobile radio. It is a system, currently in prototype state, that allows anyone to have their own radio station, broadcasted among wirelessly capable devices, some in cars, in an ad-hoc wireless network. The system can become aware of individual preferences and is able to choose songs and podcasts that people want to hear, on their own devices and car stereos and in devices and car stereos around them. ”

Roadcasting
http://www.hcii.cmu.edu/M-HCI/2004/roadcaster/movies/scenario.mov