The Rear fog light I believe was available on US versions. My car has it, and is a US version not a euro version.
Its basically a really really bright rear brake light when on, its basically brighter than the brake lights themselves.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.