I couldn't see a link anywhere else, so I thought it may be of use to know that Haynes will be producing a manual for the Vectra C 2002-2006.
It will be released in October according to their website and the details are as follows...

Book Number 4618

ISBN Number is 9781844256181

For me this will mean I can finally suss out the wiring in my 05 Veccy...without resorting to my very limited TIS and un-willing to work EPC...

Could this be light at the end of the Tunnel
Regards, Rob

Admin Edit: Group Buy thread for Haynes Manual here.