My understanding is, for the e70:

1. If you have the 6FL (usb/audio interface) and/or the 6NF (smartphone integration) options, you must get a USB adapter to suit your iPhone:

Apple iPhone™ 3G S 84 21 2 158 683
Apple iPhone™ 3G 84 21 2 158 683
Apple iPhone™ 84 10 9 164 213

If you have the 6FL but not the 6NF option, you will not be able to play music through your iPhone, even if you get one of the above adapters.

2. If you have neither 6FL nor 6NF, then you need a non-USB adapter:

Apple iPhone™ 3G S 84 21 2 158 682
Apple iPhone™ 3G 84 21 2 158 682
Apple iPhone™ 84 10 9 182 792

A non-USB adapter only enables bluetooth, charging and connection to car antenna. No music play.

__________________
2009 e70 X5 30d MY10
Innovations | MSport | Carbon Black | Black Nevada | Aluminium Trim | 20" 227M | Panoramic Roof | Rear Side Sunblinds | 6NF | 3rd Row | Self-levelling Suspension | 35% Tint