Sorry Supertomy - I saw your PM, but didn't get back. Can't seem to use this from my phone...
Anyway, I did not ever get an answer, but to clarify, I have a standard USB socket in my glove box, no jacks, mini usb or anything. I'd love to find out if there's an answer.
I also tried hooking up my old iPod, but it doesn't work. Only seems to work with never iPods and iPhones (tried with my Brother-in-Laws iPhone, and my wife's Ipod Nano (1st gen) which work, but my old clock wheel iPod doesn't.)