Thanks so much for putting this together, can't tell you how helpful it is!
Just a thought, you might want to add cdv delete, clutch stop, transmission mount, and rogue short shifter. While these aren't glamorous mods, they can make a tremendous positive impact on the performance of the Z4M. (IMO)
here are the links:
cdv
http://www.zeckhausen.com/BMW/Z4.htm
clutch stop
http://www.leatherz.com/Merchant5/me...tegory_Code=Z4
or
the diy version: (second post)
http://www.m3forum.net/m3forum/showthread.php?t=179858
transmission mounts
http://leatherz.com/Merchant5/mercha...4_transmission
rogue short shifter:
http://leatherz.com/Merchant5/mercha...4_transmission