Yep..... bolt pattern has remained the same. 4x100
Lug bolt diameter and thread pitch has changed, since 7/06 I think.
BMW changed from a 12MM x 1.5 to a 14mm x 1.25.
http://www.txwerks.com/servlet/Detail?no=47Texas Speedwerks is the only company with a conversion kit, that I know of. If you read through thier site they explain in detail about about the science behind how the wheel stays put to the rotor. It's not what you think. :?
To answer your question Jack, if your 06 was produced BEFORE July, they SHOULD fit!
Clear as mud I'd say.
~Sean