I want to this myself as there are kits with single electrics on eBay for about £75. From what I can see its pretty straight forward and don't even have to remove the bumper on the estate but I'm a bit nervous particularly about the electrical side! I'll be fitting single electrics and the eBay seller says they can supply wiring kit dedicated to my car... any advice please? Thanks!

this fitting site may help
http://www.fittinginstructions.co.uk/