used the ZHP 6speed with JB lightweight flywheel, very similar to what is in the Z4M and used a standard M3 rearend, only difference is the adjustable lower control arms. New bushings all the way around the drive train, went with Bimmerworld solid rubber motor and Rogue tranny mounts, all OEM in the subframe and diff. Definitely transfers some vibes. I have a little extra vibe at 35-40 mph I can feel in the seat, might be the driveshaft which got chopped, or it might just be the solid drivetrain mounts and some harmonic. Not sure, will figure it out. Under 25mph and over 40mph it's smooth as butter so will report back when I figure out what's up with that.
05 ZHP, Epic tuned s54, Euro headers+Sect.1, Dinan 3.91 and a lot of other things