The Bovensiepen Spider is a 430bhp BMW Z4 with Alpina DNA Motoring A new company built by the family behind the original Alpina has turned the BMW Z4 into a 430bhp spider with styling from McLaren P1 designer Frank Stephenson. Only 99 will be built. If you remember the old Alpina, before BMW took over the name, you’ll probably have a good idea of what the Bovensiepen [...]