M-Performance rear diffuser arrived yesterday, just in time for Christmas and is now fitted. Took a little longer than I thought, mainly due to the amazing about of grit and dirt under the stock piece! Total time, about 30 minutes.
Stock M6 Gran Coupe diffuser
The diffuser is held on with 3 Torx T30 bolts along the leading edge
and two expanding plastic clips at either end
So 5 fastenings in total
The rear edge clips into the bottom of the bumper, with the diffuser removed the bumper is quite flexible.
Stock piece removed
New one in place, not easy to see as it was dark and the flash reflects a lot from the number plate.
From the side it's more noticeable
A reasonably subtle mod, but I think it looks a lot better, not as aggressive as the Vorseiner, but enough for me.