Lol. I bought two of these, only in the light grey:
https://www.ebay.co.uk/itm/124963055945
There are aftermarket and genuine Merc ones available, new or used, but they all seem to be the same price.
They go in place of the grab handles, and there are videos on how to fit them. Takes a bit more persuasion than you’ll want to exert on your nice new luxury car but it’s ok in the end. Having two is quite handy.
Mine is nice and smooth since the engine and tranny service, and I put in a new battery. It was on the original, which at 9 years old had done fairly well. The stop/start was barely working even though it started fine, and the battery test showed it was only giving out 400A instead of 800. With a new battery the stop/start light goes green almost straight away if you don’t have the heating on, and there’s no judder whatsoever when it does.
Do you have the AMG sport kit on yours?