Ok so I took the door panel off again today to have a better look at the front speakers and also managed to take some better photos so you can see just whats there.
You can see the distance from the window glass to the speaker bracket is just over 2" (55mm). I have fitted a speaker adapter which I picked on from Ebay for £7.99 and this then gives just over 3" (80mm) clearance. The other photos just show the speaker in various angles.
Ok so I replaced the bulbs the other day and obviously had to remove the lights from the car. I noticed today however that there are quite big gaps at the front of the lights between the lights and the bodywork. Not sure if it was like this before I removed them or not. The thing is they seemed to fit back in pretty easily and all the screw holes matched up easily.