Hi, I have one on my RS. Laurence is the man to advise you on wiring. The wiring colours on my rs were not as the manual I used laurences tre method.
The gear indicator is a bit slow,but is still useful.
The way they work means that if you are not reving much then they can take a second or 2 to decide what gear you are in. If you are reving high then it is quite fast. the video is me and if you look carefully you can see it change 1st to 2nd (but i did scream it) It can also be slow when changing down,as the slipper clutch changes the revs in relation to the wheel speed and therefore confuses it. It is useful to me as I glance and see what gear i am in before i brake and change down for junctions etc..
Cheers .....just a old piece of 5mm ally i had lyin around, tried various (cardboard) shapes before deciding on that one....trimmed , polished and stuck a piece of carbon effect on...siliconed the indicator into the hole, stuck a bracket on the back and fixed it to the plastic trim piece thats held on by the visible allen screw, the screw/hole is not visible if i remove the indicator as its up behind the clock....did you get all that....