Nice and easy for fitting reverse sensors! I bought a set off ebay for about £16. The colour match wasn't too bad, and the display plugs into a cigarette lighter for power (I then have an on off switch) or I can wire them into a live feed for permalive.
Basically you just need to first find where you want to drill the holes, later cars have got little marks in the back of the bumper so you know where to drill. just use a pointy instrument to push this out so you have a bump on the outside of the bumper. Take the drill and cut the hole. Pop each of the sensors into the hole with the angle adjuster behind it (make sure that you have the sensor flat).
Then you need to remove the rear panel in the boot, so remove the trims from the boot catch area, then prize out the panel. You need to find the reverse wire, and then strip the insulation a bit, or cut it all together. I cut the wire, then twisted the positive feed for the sensors on one half of this wire, then used a butt connector and crimped the wires back together.
You then need to find the earth point and attach the negative wire to this point, just release the bolt a little, slide it on, then tighten again.
Look down the corner of the boot, you should have a rubber grommet, cut a small X into this with a knife, and then feed the wires from the sensors up through this hole and plug them all in. Attach the box to the wheel arch or somewhere solid and leave it in situ. If you have a hard wired panel (rather than wireless like mine) you then need to plug the wire in and run it to through the headliner to the front of the car and then connect your panel.