Powerflex Rear Subframe Bushings are the ideal replacement for the bushings on your Z3. Not only will these provide an improvement in performance, but they're guaranteed to last a lifetime!
Powerflex has extensive experience in automotive suspension and chassis systems and has combined these skills with advanced polyurethane manufacturing techniques. Durometer is standardized per fitment and location, so you can rest assured knowing the design engineers have selected the optimal urethane hardness for this specific part.
Note: Powerflex copper-based grease is supplied with every bushing set, and they will rarely need re-lubing due to the unique design features built into the material to hold the lubricant.