MPE50, it should be there driver side, kind of hard to see/feel. It is flush (no pun) mounted with a large "plus tip" slot for a screw driver. I was in the neighborhood just this weekend (07 3.0) For what it is worth, to get as much of the fluid out, I drained the system, refilled with straight di-water, and then ran the bubble removal sequence (x2). Hope this helps.