Thanks I'm going to try the software update you linked me to this morning as I see that solves a R/T button bug.

I've tried taking out the DAB cables but the mystery deepens and relying only on the 6201 C cable that you posted. The cable I thought led to the amp doesn't in fact, and instead leads somewhere else unidentifiable on the right hand side of the trunk. The 6201 C doesn't hook up to the available connector and I can't see any way of hooking it up directly to the amp.

Incompatible connectors:




Original amp connections: