BMW i8 Spyder faces development challenges?

After it has been rumored that the BMW i8 Spyder has been greenlighted for production, Autocar UK reports that BMW i8 Spyder is facing “major challenges” in engineering the vehicle. A spokesman says that incorporating the carbonfiber-reinforced plastic bodyshell construction of the i8 into a convertible format was proving problematic. “The last architecture presented some fairly major challenges, to be able to produce a convertible in that format. The rigidity was hard to find with that particular architecture.” It seems like there are more bumps on the road in the development of this 2 seater, open top, plug-in hybrid vehicle.