This is a couple weeks old, so I don't know if you got this resolved... but a co-worker of mine got some nasty curb rash on his 335d and took it to BMW to replace under warranty. The claim was denied because apparently they only replace the rim if it can't hold air.

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2010 535i, Alpine White, M-sport, SAT, Premium, CA, DOB: 23 OCT 2009