WOO HOO!!!!
Sucsess!!!!
Right. Screwed it all in and it STILL didn't fit. Was only 1/4" off though.
SO... I tried to work out that the problem was. The HU was too high up. So I looked at the screws I had fixing the brackets to the HU and they were the factory standard countersunk ones. so when they screwed down, then pulled the bracket into ONE position (i.e. too high up)
... I got hold of a few DOME head screws, same size and everything. Screwed them in but kept the bracket in a position I needed it to be in and it is now border line spot on...
So the answer is...
Remove ALL the factory cages, they are useless!
DON'T screw it to the dash cover/fascia thingy...
ONLY screw the HU to the cars brackets and the brackets to the car.
Then put the fascia on and adjust the screws holding it to the bracket accordingly.
Oh and also, DON'T try to do it at night when you are tired and just start getting angry as you will only make it worse.