I have had my empeg for about 8 months now, and there has only been 2 times when I have known that a car next to me has had an empeg. But I would like to be able to trade all of the mp3s on both devices. So, just by being in range of someone with a AP/Card in their empeg I could get all of their songs, and they could get all of mine. The RIAA wouldn't be too fond of this idea, but the chance of the few cars with WiFi ever comming within 300 feet of one another isn't very likely anyways.