Any advice on getting rubber mats back to black, and don't say back to black, tried that, holy that makes them slippy

And is it work clay baring a silver car, can you see the difference? (before I give it a whirl)

A scrub with nail brush and a good all purpose cleaner like Meguiers APC, or Tesco Daisy APC,

Once dry, I Then I give them a pray with 303 Aerospace Protectorant and left to dry



As for claying, its paintwork preparation so it doesn't matter the colour, polishing will be better and wax after will last longer IMO

Firstly, you need to give them a really thorough clean with APC (all purpose cleaner) then let them dry completely.
I'd be inclined to try something like 303 Aerospace protectant, spray on, wipe off and leave to dry. Shouldn't leave a slippery finish.  ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass

You clearly have far quicker fingers than me Nick  ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass

But both offer sound advice though

Cheers will give that a fettle...