R8 with RNS-E and B&O Sound. How to add Parrot CK3100 car kit

HelloI have an R8 with the incredible (!) RNS-E 2G head unit and B&O soundI have bought a Parott CK3100 car kit off the bay of E for the princely sum of £40 and when it arrives will be installing itHow do I tap into the speaker line though for the telephone sound, as the ISO part of the Quadlock doesn't have any speaker connectorsPlease tell me I don't have to run a speaker level cable to the B&O amp in the back and tap into it there?Thanks