Hello,
I have just installed the AUX cable to my Cooper S 04 with single CD Radio Boost.
Got the cable from ebay for £40, part number 65 12 0 308 752 which matched the part number my local BMW dealer and they wanted £60.
Took me about 40 mins to install.
I removed the glove as shown in the RHD DIY guide which was easy enough.
Once that was removed i used a small mirror to see the back of the headunit and locat where the AUX plug needed to go.
I was going to run the cable as shown in AUX guide but decided to run it to the glove box. There was a plastic push out blanker close to the AC knob.
The hardest part i found was attaching the AC pipe behind the glove box back onto the AC connection, still not 100% sure it fully on

whats the AC connection used for ?
Thanks for all the help and DIY guides !!