Just been speaking to Kev at Triple R, basically to make sure that everyone is on the same page, as I have had several different emails about it.
Kev will be doing a rear diffuser COVER with the fins moulded in as 1 piece. What this means is, it will be about 2-5mm thick and will fit over the existing black diffuser to a precise fit. It will be smoothed as one piece and means that the tow eye cover will also be covered (creating a smooth look)
The whole panel will fit OVER THE TOP of the standard rear diffuser and will be held in place by screws underneath and some strong 3M double sided tape at the top. I have been talking to Kev and it will be supplied in black as that is the finish of the mould that they will use.
He estimates it will take less then 20mins to fit on your driveway without the need to remove the bumper. It will also be less then £100inc postage so it is still in a good price range. He will be sending Dan and I some pictures once he has sorted it.