Managed to drill out screws holding number plate lenses and full unit holding everything that goes on back door. But came across this thingy thats red in colour with spring inside it that was attached inside the whole cabboodle...The thing is I touched what looks like a button on it and it clicked, so thinking awe naw prised button back out and it came right out with jack in the box spring attached on it...hope its not an air bag switch or the like...The spring as I said is actually a coil so its electrically pulling on a shinny plate as viewed through a hole in one end..Nothing showing on dash when ignition on... Got Siegel Robert on thingy...

 

Possibly the warning beeper for the tailgate Goggsy, but if it is, I don't know why it has the spring or 4 wires.

 

That's what I'm thinking myself and why its on outside of door...Anyway filled it over with Arildite, well Toolstation's alternative at £2 odds, and all's screwed back together again...Job done with new lamps and screws...

 

Yes, it is the warning beeper, but it is also a thermistor, that is what the extra wires are for.