In reply to last post, the mudguards - once on, both sides have two visible self tappers facing the wheel and one 'push' clip on the bottom that is fastened to the 'fender'.
But the good news is that in fact the bumper does not require to be removed to fit the OEM mudguards - going cheap just now from Coxmotorparts!
On either side remove wheel, remove clips from fender - 3 on left, 2 on right, remove lower of the two self tappers on the bumper lip, ease the 'fender' down from behind the lining.
Cut slots as marked on the fender, drill hole for mud guard clip. DO NOT BEND EXCESSIVELY ANYWHERE!
Fit the spring nuts in the positions marked on the bumper - (Let the self tapper centre itself).
Refit the 'fender', carefully pushing between liner, fit the self tapper first, this to get fender position correct as to where it was before and ensure the self tapper is back in it's boss.
Refit push clips, I had problem with original inboard one on right fender, the metal location for it is awkward, but swapped it for the new clip supplied with kit and used the old on in the lower mud guard position. (The 'fingers had sprung a little?)
Fit the mud guards - check position below bumper - little notch to align, push up and in when screwing self tappers home making sure tight fit to bumper - tighten top self tapper first I think is best.
Job done. About £80 cheaper than dealer.