k, i've been routing around again today (im not going to give up easily!!) and i THINK i may have found the root of the problem (MAYBE)
for starter, i found this.......on the passengers side speaker there is a wire that i've ben connecting to the speakers, and the today i managed to dig this out...so it's not actually been fully connected.....(it's the wrong way rond tho! imagine it rotated 90 degrees clockwise

)

and then, does anyone know how i can get inside here to 'reconnect' the wires?

then, i followed the wires through the car, lifting up various bits of carpet, to find this little lot.......

there two different types of 'wire connectors' do u think this would make any difference? tempted to change one of them just so i know they're both the same! also i noticed that this foot well is quite damp, so they've been damp aswell (hoping the dampness will be the residue of the leaking windows, which are now fixed)
do u think, if i went round all the 'connections' of different wires, trimed some of the plastic casing off and reconnected with a fresh 'middle' bit of wire it might fix my problem??
also, iv tried to pull my head unit out and it wont budge, so at the mo the only view i have of behind the head unit is this one......

so im tempted to try the wiring before resulting in bringing the head unit out!
any suggestions?
cheers muchly! sian