I have a set of m-class xenon lights for sale. i did the retrofit myself and the ballast is attached to the botom of the light. great setup. note these are not bi-xenon, they are 2002 projector headlights with a hella ballast atached to the botom. Already wired to work on 2001 and older mls. i am asking 550 or best offer. this setup comes with the whole assembly and a generation 3 hella ballast and igniter in one box and 2 xenarc bulbs. works great.