Thanks Chris.
Yes, apologies. RCA connections. Yep, I've also got one with the theatre system although the rear roof screen was removed to fit a poptop roof. I found the rca connections as you said and it works! Brilliant. So simple! I was worried I would have take off the head unit to find suitable connections. I think I'll now get a Bluetooth device that connects to rca and then I won't even have to use the cables. Thanks a lot!
Samuel