It's a pain. I had the car on a lift and went from underneath. It took longer, but was much cleaner.

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Current Garage:
2015 Singapore Grey M6 Gran Coupe (ED - May 2014) -new car
2008 Imola Red E60 M5 - love of my life
2012 Alpine White LCI E70 X5 50i w/ LCI Aero Kit and Rocker Panels - wife and kids car

Retired:
2009 Jet Black E70 X5 4.8i Sport w/ Aero Kit
2007 Jet Black E60 530xi M Sport
2003 Jet Black E39 530i Sport