https://www.car2goblack.com/de/DE/
1 hr for 15 euro for regular Car2go in Berlin vs 15euro for....1hour on Car2go black. (Right now sounds like there is a deal on the Black service there).
Only difference is it looks like ours have been purposely colored the same as the Smart car's to increase visibility or reduce parking issues, as elsewhere you're getting a black Merc that looks quite balling.