Got one of these and it works perfectly with the BMW iPod lead. Allows you to see the screen on the iPhone....
http://www.amazon.co.uk/gp/product/B002JTWRN8/ref=oh_details_o06_s00_i00
I have this too but as I have automatic FR I find the positioning to get in the way when I put the car into park to have to sit my ipod sideways. As the adaptor removes ipod functionality anyway (you view music via head unit controls only) it doesnt really matter.