This is something of a marvel, a relic from the Ulm Design School ethos at Untertuerkheim.
This article is one of three items today which pay special regard to ashtrays.
For the 1991 W-140 rear ashtray the designers located the tray and adjusted it to the surrounding forms and materials. That meant it got a matching carpeted panel when, purely functionally, a one-piece cover in plastic might have sufficed. The Ulm attitude involved taking great care to consider going beyond the minimum so the entirety of the object’s relevant parameters are addressed. In this case it means that if the surrounding surface is carpet then the ashtray should fit in while being detectable: it has a clearly visible edge but the carpet unifies the ashtray drawer with its surroundings.
[Thank you to our Hamburg correspondent, Kris, for obtaining the photos of the ashtray.]