If you are not going to need winter tires again on your X5, don't buy them. Simply rent a vehicle with appropriate tires. Nothing worse than summer tires in winter conditions, especially for someone not trained in winter driving (which is an oxymoron, because people trained in winter driving tend to buy winter tires).

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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