Also to address the rust issue look for the air conditioner condensor drain positioned right above the splines. This is where the moisture comes from that causes the splines to rust. It would be cheaper to reposition the drain than to coat the splines.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue