I just bought the ML and it had cracked fog lenses so I replaced those and the factory fogs were terrible. Once I upgraded to the 2002-up projector headlights and Valeo HID kit, the fogs weren't doing anything.
I'm kind of a lighting fanatic, so I ordered the Osram H7, which are rebased H9 to increase lumens on high beams from 1500 to 2100 Lm. I also replaced the factory fogs with Hella 90mm low beam projector modules. They were almost a direct replacement and rallylights.com even sells the factory plugs and hardware (see blury pic below).
What I started with Osram + Hella
Test fitment
Factory plug
Finished product
The improved lighting on both fog and high beam is amazing and all components were <$180 shipped.
I'm kind of a lighting fanatic, so I ordered the Osram H7, which are rebased H9 to increase lumens on high beams from 1500 to 2100 Lm. I also replaced the factory fogs with Hella 90mm low beam projector modules. They were almost a direct replacement and rallylights.com even sells the factory plugs and hardware (see blury pic below).
What I started with Osram + Hella
Test fitment
Factory plug
Finished product


The improved lighting on both fog and high beam is amazing and all components were <$180 shipped.