Can anyone tell me if there is a plug behind the dash for the entire wiring loom before it makes its way through to the engine bay in an EL XR8? I'm hoping there is so I can replace the plug into the EEC! Otherwise there's lots of cutting and soldering to do!

So you mean you want to change the plug for the ecu? If so then yes it is part of the engine bay loom. There is plugs under the dash where it has some wiring joining the dash loom, undo these and the loom pulls into the engine bay.

I might not have been all that clear in my first post. Currently in the car there is a Haltech computer that's been wired in, just above the eec plug. What I'm trying to avoid is having to get in there and rejoin all the wires that have been chopped out. So I was hoping that I'd be able to unplug something up under the passenger side of the dash or somewhere and just replace that section of the loom. I think it's a long shot, but hey! Luck's been on my side lately...