WARNING: This page is about a different car, the 2008 BMW Alpina and 2007 BMW Alpina. However, it is still accessible from the selected car via links, so may be relevant.
Dimensions in mm
Fig 1: Front Exterior Body Gap Dimensions And Measurement Points (Front View)
Courtesy of BMW OF NORTH AMERICA, INC.
Fig 2: Rear Exterior Body Gap Dimensions And Measurement Points (Rear View)