I feel a berk - my coding was '0003 - must have found the original scan with the previous car's coding Sorry. I changed back to the A4 coding and back to A8.
0003 is definately for 4 antenna - see pics. Did not need a security code to do this.
Attachment 16324 antennas 1-4 OK

Attachment 16325 antennas 1-3 OK (4 not used)

What's the 1 in my coding stands for by the way guys ?

the "1" is for Rear Seat Entertainment (RSE)