Without knowing for sure, I think those FM transmitters are still illegal in several countries, including UK.
http://www.ofcom.org.uk/media/mofaq/rcomms/itrip/However, very recently (march 2006) they appear to have been allowed in Germany, which normally pulls most of EU with them, so hopefully this liberalisation will catch on:
http://www.golem.de/0603/44073.htmlThe FM transmitters are an easy way to connect your iPod in any car, but I hate to think about the potential disturbance, if somebody pulls up alongside your car, and switches your VIvaldi with Death Metal :-)
But that's of course another problem.
/Lennart