My OEM windshield was fine, but my OEM side window always had distortion from day one, on the front of the driver's side glass. OEM glass is subject to the same chance of getting distortion as non-OEM glass, IMO.

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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