Solid subframe bushings?

[Hujan]

I replaced the rubber subframe bushings with solid aluminum bushings on my M3 and love the results. The rear end is much more planted and stable under acceleration and there is no additional harshness or stiffness. (I also did the diff bushings at the same time; these added a little diff whine.)

Anyway, I'm wondering if anyone makes solid or delrin subframe bushings for our cars? Is there any chance the part numbers for our bushings are the same as other cars?

[Ramjet]

I have replaced my whole tail end rubber bushings to poly, including my diff mounts - superpro.com.au have the complete set for our car and ship international. Also did a few of the front end as well, but have the M3 control arms etc installed. I left my subframe mounts as rubber to keep road noise to a minimum.

I've really liked the upgrade, my Z4 is 5 years old and it has tightened/firmed up the whole feeling like new again!