[M Fifty]

Black Grills. M Performance steering wheel (the regular trim fits). Pedals. Not convinced about the gearshift - it needs a big heavy shift knob to help the shift action.

I would have considered the side gills in black too, only the stock ones match the indicators in the mirrors.

The finish on the exhaust trims is not great (on my 2nd set), so I might go down the M4 route, or possibly the faux M Performance route (the stock exhaust sounds good to me).

M Performance suspension - other options are available (but don't protect the full Warranty in the UK).

The exterior CF - meh. It's too expensive for something that's purely cosmetic.

I "might" look at retrofitting a few M2C parts.