I found one from an 325. Now that I see you have done the same thing, tell me, hows the fit?
Are there any engine contact pints that rub?
Is the hood insulated well enough that the paint is not affected?
Gary... I got one from the yard for $10, so I figured I'd give it a try, especially before I powder coat my IM and VC. So, if it rubs a little, no big deal. It's way nicer looking and that was the biggest thing for me... keeps a lot of the heat from soaking through the hood. The paint on my hood got a "dried out" look very quickly. Much improved in that respect.
It does rub a little on the very top front corner of the IM, but that's it from what I can tell. I'm very interested in maybe trying an E30 M3 under hood liner as that car has such a protruding intake (much like our cars), that it might have the correct spacing, but not sure. Unfortunately, it will be fat chance for me to find an E30 M3 under hood liner at a yard for $10.
I'm sure the dealer will want $100 for one, or maybe more as it's an M specific part.
(///M stands for Money, btw).

If you want, I can take a picture of the area where it rubs, and maybe you can figure out a way to "modify" it a bit so it won't rub. Probably won't be that hard with the liner off the car.
Do you have all the little clips that hold it in place??