WARNING: This page is about a different car, the 2016 BMW Z4, 2015 BMW Z4, and 2014 BMW Z4. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Foil (2356848)
Courtesy of BMW OF NORTH AMERICA, INC.
NOTE:
Silhouette foil (set) for special tools 2346947, 2344569, 2318573, 2348128, 2353020 and 2351398.