Ummm... aluminum IS a metal... MoS2 bonds with metals (not just iron), thus...
Thorromig
How many miles in your car? One of the things about MoS2 is that you're not supposed to use it prior to 30 - 40K mi -- I remember LiquiMoly literature to this effect, which I cannot for the life of me find.
This is another reason why very few LM oils come with a ton of MoS2, as it will hinder the break-in period of an engine (again, you're not supposed to start using it for at least 30K mi (or 50,000km)).
DriveHard:
Which BMW do you have? I've been running MoS2 in my '03 325 (M56) for just under 100,000 miles -- engine's so smooth you can't tell it's idling. Same effect in my '05 330 (M54) and the x3 (M54). Valves so clean you could eat off of them.
My friend's run it on his 530 (N52) for 50K mi and his 335 (N54 turbo). Noticeable difference in engine feel/sound after even only 20 - 30 miles (of course, once you've driven 40K miles, you kinda know how the car sounds, sooo; BTW, he was a MoS2 doubter before that day).
A couple of others with Infinitis/VW/Toyotas experienced the same thing (all cars MY 2003 or newer).
Everyone else -- say what you will, the COF is absolutely, without a doubt, reduced -- you couldn't possibly silence the engines that way otherwise, nor could you change the smooth cold-starts (even after a few weeks, that first crank is as smooth as if you'd started it warm). Also, with a number of those cars mentioned above, the first MoS2 bottle was added about halfway (give or take) into that current OCI, so maybe 3500 miles in... it had nothing to do with the oil in the car or anything else -- only change was the MoS2.