Been around for at least fifteen years, now. The switches were present with no wiring to the rear since the 80s.
Then about '91 MB started activating them. Driver's side only. My '01 has bulbs in both tailllights but only the left is wired. If it was a right hand drive car the right lamp would be wired. That way there is only one taillight assembly worldwide. Both of mine are wired to the brakelights and the fog function is disabled. RLE
