After some support here I decided to put the splitter on today. Im the least practical person ever (can barely change a light bulb!) and the fittings were not supplied so I wasnt confident, but....
http://chrisharrison.smugmug.com/photos/24749966-M.jpg
More pics here... http://chrisharrison.smugmug.com/gallery/534854http://chrisharrison.smugmug.com/gallery/534854, just noticed how clean it still is actually, havent cleaned it for a week (about 400 miles), NXT wax really works wonders.
Splitter looks great in the flesh, drilling the holes was easy, attaching it to the car was easy but damn was taping it to the car to get the fitting shape hard work. I never raised the car at all and just had a screwdriver and a few self-tapping screws to work with. I can now officially say that if I could do it with no help, virtually no equipment and not raising the car anyone on the planet could do this!