I think the BMW Performance kit is a development of the tried and tested B4S damper, selling it as a 'replacement' for OEM Sports is the nearest marketing approximation for them.
Regards the question on bumpstops, yes you can get away with the stock length ones but its not ideal, I've been there and tried it.
The ones that BMW sell with the Performance kit are much shorter than OEM MSport so they must think its a good idea.
Originally Posted by parapaul
Interesting... They're specifically sold as OEM replacements for vehicles with sports suspension - which to me, would suggest sport or MSport rather than an aftermarket setup. I have no doubt you're right though, having seen them.