I have similar ebay unit, the halfords plate will need a huge trim think in depth it ended up being only 1.5inches deep at the most I just did it quickly with angle grinder. Put in a screw in the side so the plate no longer moves and then clipped it into the centre dash.
Also remember to switch the red and yellow cable round (if I remember correctly). Also ground the handbrake cable, either to the chassis of the double din or to one of the earths on the ISO plug thing.
On my unit I had another problem, I needed aeriel adapter and when the arial was in, it would not allow the unit to sit back fully as the aeriel would hit the middle cross section of the cage in the centre console, so I had to take the dash and centre console somewhat apart. Remove the huge box the double din units sits in and cut the centre cross bit out (right at the back, behind where the double din would sit). This allowed the unit to go fully back. The cross section of the cage in the centre console, it just seem to be a support/strengthening point to the cage but its not needed and theres a good 3 inches of space behind it for additional cables etc... if you need it.
TV system is not worth installing, as a small aeriel will not work you will need a proper kit (which are quite big and go under your roof carpet, usually £100+ just for the kit), and crimp the right fixing on, too much hassle and no real point unless you really want it.
If your unit has GPS on it, a good point to fix GPS too is, open the cover on the passengers side to where the glove box is, there you can place the GPS module ontop of the glovebox mould, or if magnetic, attatch it too ths metal fixings, which is where my additional fusebox and GPS module are.
As for GPS software I would recommend iGo8 it works very quickly and has an autodetect setting to work out the com-port and buad rate of the module, plus tomtom software is very tricky to get to work on these as the settings are unknown and alot of other complicatons with the whole WinCe system.
End result should be this:
(should stick out a tad, with the clip on frame to neaten it off)
(using iGo8's speedo and altituden)
Unit is great, cheap chinese unit was about £180 not had a problem at all in the 6months of having it.
