I have got PSS9 on my audi TT in 2001
the coating was yellovish and after 4 years corroded, the springplates couldn't move anymore.
It seems that new PSS10 has improoved coating... but maybe HR in inox is better?
Will negotiate with HR and bilstein to obtain a mixed kit with 335i front and M3 rear.
Unfortunately there is no bilstein ride control for M3