The new plastic upper arms that are standard on the brand new X4F'25!
These upper arms have no graphite piece in them (like the standard X4'24 upper arms) and thus, naturally are more flexible. Customers have asked about the compatibility of these arms with the X4'24. They are compatible! I use them on lower grip conditions, on a dusty and/or "green" track to improve drivability. They make the car very forgiving, but a little less sharp, less reactive. The arms can be used on both low grip asphalt & carpet conditions.These upper arms are a good option regardless of what lower arm you use.
A bonus is that these arms are more durable than the CFF upper arms!

Part numbers:
302134-C
302144-C