This topic has been getting lot of attention and until BMW allows people to thoroughly test the performance and limitations of the range extender the doubts and concerns will continue. I gave my take on the REx issue on a recent
blog post and have asked BMW for an opportunity to test one once they are ready to allow thorough testing.
This is a big issue for many people considering the car as they don't know if the range extender will be robust enough to warrant the $3,850 it costs here in the US since there will not be a manual override here due to CARB restrictions.