I'm 2 days from picking up a used 2010 MCS with the Mayfair package (fingers crossed). The car has the all-season mats but I want to buy the factory carpeted mats as well.

According to option codes the car came with;

423 FLOOR MATS, VELOUR

Is this a special mat for Mayfair or standard black carpeted mat?

 

There's several velour floor mat options; all depends on your interior color and what color trim-piping of the mats you want.
If you look at RealOEM.com, pick the R56 platform, and then head to Vehicle Trim --> Accessories & Retrofitting --> Floor Mats you see the available kinds.
Your local MINI dealer will be able to help you pick the proper ones, as they have several examples on the show floor.

- Erik

 

I bought the black carpeted mats for mine and wish that I had saved the money. For an excellent set try Cocomats. 4+ years old and look great.