Found the instructions that I was looking for ( I knew I'd seen them somewhere) -
http://www.bimmerfest.com/forums/attachment.php?attachmentid=215697&d=1264113784
I phoned my local friendly BMW dealer on Thursday afternoon and was quoted £383.83 for the deflector and was told that I had to replace both the black and silver covers. In the end I bought a new OEM deflector kit off Ebay for £200 + carriage late Thursday night and it was delivered at 8am on Saturday Morning.
When I took the silver covers off the car I realised that the fixings are already there for the screws - all I needed to do was drill two holes in each of the silver covers. Whole job was done in an hour or so and it was very simple. Only thing that some people might not have lying around is a T20 torque bit for the fixing screws.
