Unfortunately the bumper unlike most is made of a dimpled soft compound. Most cars have self coloured bumpers which with judicial use of a heat gun pushing out the depression and an aerosol of paint can be repaired.
I stupidly did not cover the bumper when loading some slabs and scratched the bumper. It appears to be a case of a new bumper as the dimples are removed if an attempt at rubbing out the scratch is attempted.As to the sensor they are a push fit if they follow the norm.
The joys of a throw away society.