A bit pricey at 2,295.00 pounds especially considering AC Schnitzer is likely as usual just rebranding someone else's suspension option and marking up the price with their name:

For the 3 series we offer our ultimate suspension package - AC Schnitzer RS adjustable. Perfectly set up for fast road use, but equally at home on track days, this package delivers greatly improved handling and steering with improved ride quality - a seemingly impossible achievement arrived at by the use of higher quality components and the setup skills of AC Schnitzer chief development engineer and test driver Manfred Wollgarten.

Adjustable for compression damping, rebound damping and ride height. Please choose the correct body option from above when ordering. Not for X-drive models.

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Regardless, it's an F30 suspension option.