Just bought a new 35is and playing with all the new toys and plugged my i phone 5c into the USB port and summond up the external device (previous car showed it as auxilliary device) and it recognised all my play lists straight away. I think itr depends on what multi media system you have rather than the phone and or cable. I used the cable from my charger.
PS I recall the manual saying something along the lines of it may not work if the phone is also paired via bluetooth at the same time so may be worth trying to un pair it.