OK so in the end I got my sensors fitted, took a few hours but that was because I separated it over several days...
so for anyone who wants to know, Orange and Green behind the left hand side boot trim panel is the wire I used...
I cut the wire with a pair of pliers, then stripped back about one inch either side of the cut to reveal the wires, and twisted them on themselves. I separated the same from both the live and earth wires on the sensor kit, and secured the earth in between the bolt head and the nut at the earth point, then wrapped the live around the twisted green / orange connector, then slid both ends into the crimp butt connector and squeezed in the middle and once at each end.
I bought a set of "heat shrink crimp butt connectors" which I tried to heat with a lighter, but could probably do with doing a proper job later, but for now its a good job.
I worked on a premise of putting the sensors A and D (outside edges) 6.5cm in from the outer edges, and then gave them about 40cm between the outside and inner sensors (there was about 36cm between the two inner sensors).
Pictures will be uploaded soon, but for a set for 16.50 off ebay, and the fact that I just plug the LCD receiver into a 12v output, and jobs a good 'un.