I fitted a towbar to my previous saloon, wasn't as bad as I had thought. Took about 3 1/2 hours, but didn't have to take the wheels of or remove the lights as previously thought. heres a rough runthrough of what to do.
1)Remove the spare wheel compartment cover.
2)Remove the two nuts holding the black plastic trunk trim, just behind the spare.
3)Remove the four luggage net hold down clips.
4)Peel back the carpet from around the sides which is also pushed under the black plastic trunk trim. This is spring clipped in place. There are also two plastic screw clips in the top of the liner above the shock towers.
5)Behind the trim you will now see a vertical line of four nuts with plastic point covers on the protruding bolts. (Beneath the rear lights)There are also two more of these in a vertical line inboard of the four. (six total each side)pull off the plastic cap and remove the nuts.
6)Remove two screws underneath the valance, in board of the exhausts attaching the valance to the frame.
7)Remove two Torx screws each side inside the wheel well holding the carpet liner in place.
8)Remove the Torx screw that is behind the liner. This holds the valance.
9) Pull the sides of the lower bumper away from the side of the car.
10)The whole unit will now pull off in one piece.
Fit the towbar and then re-install everything
Hope its of some use..