MrTignale

It was the Gadgetman kit, bought from latest-bidder on ebay for £14.95. It is a good product.

Many thanks for the advice. I have successfully finished the job. I found the little inserts in the boot lid trim panel that you can pull out and gain access to the reversing light bulbs. This told me that the wire for the reversing light was either yellow or purple, with the earth yellow/green. There was no way of connecting my multimeter, but by lucky chance, I found that the yellow wire was the one for the reversing light! I used an in-line connector and connected the live wire for the sensor to the yellow wire just before it entered the plastic cover on the left-hand boot hinge. Bingo!

Hi, I am just doing the same job on a 2009 59 C5 VTR+ saloon, and also having difficulty identifying the reversing light wire. The reversing lights are in the boot lid, and the harness runs behind a plastic cover on the left-hand hinge. There must be about 8 wires in it. Can anyone tell me which colour wire I should be connecting to, so that I can avoid taking all the trim off the boot lid? Many thanks.