Engine oil gets contaminated by byproducts of combustion over time. Usually a good idea to change the oil before letting it sit so there is less risk of engine damage due to sitting. Not the same issue with other fluids, just the engine oil.

Also, putting it on blocks can prevent flat-spotting of the tires.

When you recommission it you should check over everything, seals can dry out, etc.

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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