My 2007 has been pretty good so far. I purchased a VERY late build 2007 (August 2007) and would avoid an early build personally. I also pulled the service records and examined them closely. If you see a service record with lots of "in service" dates I wouldn't buy it because that means reliability issues. My 2007 4.8i had literally service and 1 headlight failure fix so I selected it from a list. Good luck!

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The Present:
2014 Audi Q5 TDI Prestige
The Past:
2013 Lexus GS350
2013 VW Golf TDI
2007 BMW X5 4.8i LOADED & Loved
2009 VW Jetta
2008 VW Touareg VR6
2005 BMW X5 3.0i
2005 BMW Z4 3.0i
2004 BMW X5 3.0i
2003 BMW 325i
2000 Ford Explorer Eddie Bauer 4x4