Hi to all, the on going saga of my parking sensors is over, I moved all the sensors from beneath the bumper to the top of the bumper and held them in place with masking tape then had a reversing session to make sure everything was ok, next job remove all the wiring and sensors then drill the bumper the idea was to cut the hole in the plastic bumper with the cutter provided then open up the hole in the metal part of the bumper with a cone cutter the cutter I had was marked “HSS” now in most countries this means “high speed steel” but in China it seems to mean “Hardly suitable for steel” it burnt out just looking at the hole, luckily I have a good tool shop near me where I bought a set of three “HSS” cone cutters at £ 12.50p these lived up to their claim and the job was done, one thing I did find was that due to the thickness of the plastic and the steel plate the clips on the sensors tended to push sensor out of the hole so I used supper glue to hold them in place, every thing now working spot on, as for the holes in the under bumper I’m going to fill them with clear panel lamps to come on with the reversing lights. Good luck to all of you contemplating this operation but do place the sensors in the main bumper. Best Regards sillyboy