Is this what you mean? the struts themselves?
Or strut tower cracks
Lots of BMW suffer with this hitting a pot hole hard can cause this. Can be solved with a strut brace if they are little. Otherwise Welding up, grinding and repainting is a solution if they aren't too bad. The strut towers can also be replaced.
BMW did make a reinforced top mount for the M3 CSL that can be added to the Ms.
In the 10 years of being on here ive not seen it recorded that much as im sure a lot of people don't want to document this as most move through the forum for sale but I have seen a handful of cars with this issue.
Loads of E36 3 series have issues with this but pretty much all sports cars suffer with it with stiffer suspension
Guide here
/Volumes/Marketing/Marketing (TH)/Marketing/SOCIAL MEDIA/GLOBUS GROUP HEALTHCARE/Made in UK/Made in UK finals
Most recent big news items with this is the Porsche Cayman 981 GT4s having massive failures and Porsche basically not supporting the issue.