It is called negative camber, and is described as the wheels leaning in at the top. Positive camber would be the wheels leaning out at the top. It promotes better handling, and is designed in by BMW. This is a bit simplistic, but one way of thinking about the logic of it is to imagine a vehicle heeling out (tipping) in a continuous sharp turn. That is a natural function of the vehicle cornering. As the vehicle leans, so does the tire contact patch, thus reducing the effective contact patch on the outer tire just when you need it most. Negative camber improves the contact patch on the outer tire in corners because of the angles and forces on the tire, and because the tire has less tendency to roll under. What it feels like to the driver is a more predictable, planted feeling.

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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