OK, it looks like this job should be put to the back of my list until I have more information! I don't have the original bugeye mirror switch and haven't checked where the original wiring is, but I think it is under the centre console. I presume the Toyota 183574 switch I do have uses a different plug/socket fixing also.
The bit of the door card which houses the switches looks like it should screw into a bracket. However, this is missing and there's nothing to attach it to. Is this bracket easily available does anyone know?
TIA
