The boards, which usually carry typical advertising, are programmed to identify approaching Mini drivers through a coded signal from a radio chip embedded in their key fob. The messages are personal, based on questionnaires that owners filled out.
This sounds like we are approaching the Minority Report world:
Everywhere that John Anderton (Tom Cruise) went, his eyes were being scanned for identification. I’m not talking just about restricted areas - he was scanned entering the Metro, driving home from work, and even walking into The Gap. The advertisements called him by name: “John Anderton, we have the ideal vacation for you!” and “John Anderton, wouldn’t you like a pint of Guinness?” But not even a pint of Guinness would have soothed my nerves after hearing my name called out all day long. If you thought spam was annoying, you ain’t seen nothing yet.
The Mini story via Pondering Primate.