all sorted.....
i can know have the camara in use whilst driving or with a flick of a switch it will only operate when in reverse.
to do this you need to use a 3 pin rocker switch.mines hinned away in the armrest cubby.so first off you need to mount your camara.i opted for the rear tow eye cover.i removed the cover and drilled a hole big enough for the camara to fit snugly in place.i then run the cables from the camara into the boot..
i found a earth point and power(I added a BLUE wire) using the n/s/r reverse lamp wiring.once all was tested i move onto re wiring so it could be used whilst on the move and not just as an aid when reversing.
i found a live feed to the stereo and added a wire(red) from that to the new 3 pin switch.this wire was connected to the left hand pin.
i then run a wire(brown) from the centre pin of the switch to the boot.whilst there i disconnect the power lead to the camara from the reverse light (blue)and run that to the switch and connected this one to the right hand pin.
you should if following this guide have 2 wires from the switch running into the boot .(blue from the live on the reverse lamp to the switch and brown from the switch to the power the camara.)
right time for the test,switch turn on to the right and reverse selected and bingo it works.
knock out of gear and select left on the switch and camara comes on .
the wire i run from the centre pin off the switch was the connected to the live camara wire.
the hardest job i found was writing the guide so i am sure if i can do it ,so can you.
hope this helps.