Haha! Yeah, I did. Posting this question was my last option.
I'll look back over the guide but I'm sure it only mentioned splicing the earths together.
If you have the Bose, then the speakers have an amp which requires a remote signal from the HU to tell it to fire up.... so no spliced wire to the amp then no sound....
If the HU is firing up and staying on the you have earthed it ok, did you plug in all 4 RCA leads, Red / White / Yellow / Black ?