The thin plastic edge of the adapter plug must be cut off, otherwise it will not fit on the existing (BMW) connector of the RT! Then you should back up the associated connector with a cable tie against ünbeabsichtigtes solving!
I have the following equipment is installed with this adapter in my RT: XOMAX XM RSU208B Bluetooth Car Radio (SD card slot, USB) Black / Chrome
Further details on the installation, see my review for the above car radio!