Many thanks for everyones advice.

I popped home at lunchtime today, ripped the dash apart again andset to work.

I cut the blue wire coming out of the headunit loom (as if defusing a bomb movie-style) and crimped the two ends back together in a female bullet connector so that I could then plug inthe male bullet connector coming from my amp.

I now have sound from the front speakers.

For some reason though, nothing from the rears despite connecting it up as per the Genesis instructions. I tried plugging the rear RCA's into the headunit and got sound, but nothing when trying to get the amp to automagically sort things out. Any ideas why?

Anyway, front speakers working is better than no speakers working