I tried this to no avail with my BBS's...maybe their centers have a tighter spring? I did find, however, that a 2" suction cup worked perfect. The BBS caps are very smooth. Stuck it on, and pulled. Out came the cap!
Current: '16 GT4
'13 F10 M5, Alpine Weiss III/Sakhir Orange Full
'10 E60 M5, Space Gray/Black