Doing some W140 research for no reason in particular, and noticed that some of the early cars had what looked like 2 additional antenna caps at the rear. They come out when you engage reverse gears, and were meant to be visual guides to make it easier to see the corners of the big Merc. They were only around for a couple of years, and were replaced by the electronic parking sensors we know today.
This is a very Germanic example of incredible attention and complexity lavished on something seemingly trivial. I mean, is it really that much easier to see the rear corner of the car with these 2" antennae? Doesn’t matter. You’re driving an S-Class. You are powerful. When you make a move, the world moves out of the way for you.