EDIT: These will fit E9X M3. Here is a thread:
http://www.e90post.com/forums/showthread.php?t=259195
He is running 19x9 ET10 F, 19x10 ET10 R.
Here is another:
http://forum.e46fanatics.com/showthread.php?t=675406
20x9 ET15 front.
I have a set of 19x8.5 ET15, 19x10 ET25 BBS RS-GT's in Diamond black for sale. They are m5/m6 fitment. They were originally on a BMW 645 for 10k miles. They had the cars original tires on them when I bought them. They are in great condition. There are a few marks on the lips an one scuff to the face of the wheel which can be seen in the wheel 1 pic.
I believe these will fit e9X M3's and E90's. See post further down the page for more info.
$5000 before tax and shipping. The 10" rears are backordered on tire rack.
These are BBS' top of the line wheels along with LM's, LM-R's, etc.
Here are the pics:
Wheel 1:
Wheel 2:
Wheel 3:
Wheel 4:
I'm going to say $3,200 shipped to any where in the US or best offer.