My stereo's stopped working :( It says incorrect wiring or something similar, it's an aftermarket JVC unit, but I'm wondering if it could be related to one of the door tweeters (rear passenger) being pulled off and the speaker / lead falling down into the door. I've no idea how it happened, clumsy passengers as it was a tad loose, but since I noticed it missing, stereo's fubarred.

Could there be any other option?

It could be the speaker cable. if the positive and negative are touching the stereo will shut it self down to prevent a short. try separating the positive and negative cables. or cut that side off the ISO connector on the back of the head unit.

Cheers I'll give that a go on Sunday morning when I pop home. I love nicking my dads tools :p

You can unplug the tweeter plug by prising off the rubber hose cable cover near the door hinge which is visible with the doors open, there 1 a 3 way connector for the lock, a 2 way for the door shut switch (for warning light and interior light) and a 2 way one for the tweeter. If you unplug it here you dont need to take anything apart.