YIKES!
But well known retailers sell similar products, like Tescos sell the FM Handsfree kits that work in the similar way - through the radio.
Are you positive that they are illegal?
Trust me - get the MP3 Transmitter where me and Furki got it from.
I orderd it at 4pm and got it the next day from the guy who sells them!
For £11.99 you cant go wrong - and it works puka!