My stem is pretty long. Sorry you have short one. I've seen ads for stem extenders but I can't vouch for their safety.
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2016 340i XDrive, EBII/black, 6 MT, M Sport, Track Handling, Cold Weather, Tech, Lighting, Driver Assistance Plus.
2012 Z4 35i, ED 2/24/2012, Melbourne Red Metallic, Black Leather, Carbon Trim, 6MT, M Sport, CW, PP, PS, NAV, CA.