Cant see any of the pictures on your recent posts. Here and on the spring sag post aswell.
Our control arm bushings are fluid filled for comfort. Have had mine checked for leaks and mine are ok. If they break or leak i plan to change my arms with e90 M3 control arms
The arms are similar with M3 arms with the difference in bushings. M3 arms have balljoints and give better steering feel and some camber too.Also its claimed that they last longer aswell. They bolt straight in. There are aftermarket options for solid or poly bushings that replace old ones on existing arms. They are cheaper on parts cost but more work for the mechanic to install.
First link i found for the arms upgrade:
https://www.turnermotorsport.com/p-3...2-e9x/?pdk=AwE