Think it's the old game of making things that geeks do to for the rest of the world. Should not be very hard to add a chich jack to your normal car-hifi and solder a cable that goes from the headphones to to normal chinch - thus does not add controls over the iPod to the steering wheel. This is a nice feature. I wish the industry would build a standart for this, so that you buy a portable player that hast the xyz-jack to hook it to you cars remote. Mhhhh... think will need a new car, if this happens. Renault won't build controlls to their steering... at least not for Twingo.
