What are those two chrome "buttons" on some 1991 - 1999 Mercedes S Class saloons?

Question

I have noticed some of the 1991 - 99 S Class cars (W140) have these two small chrome "buttons" on the extreme corners of the boot. They actually look more like retracted antennas - what the heck are they - you don't find them on the W220

Answer 1

I think they stopped installing the chrome parking pegs in 95. I thought they were a waist until I drove my bosses car a 92 S320 and was surprised how helpful they were.

Answer 2

On certain 140 bodies, those little chrome rods extended out of the vehicle when in reverse to allow the driver to have an idea of where the back of the vehicle was. They were huge tanks especially the LWB, and some drivers needed a little help