As a former engineer with both GM and Ford, I have to thoroughly refute what a previous commenter has stated about likely explanations. With the technology of the powertrain/fuel source development that far along, that far advanced within a viable vehicle, crash-safety and equipment regulations would not have removed this from the marketplace. The "skin" and tub/framework of the vehicle would have been either reworked to comply or the powertrain/fuel source would have been adapted to fit existing car lines that meet crash-safety and equipment regulations. There are plenty of examples of "hurry up" retro-fits in Detroit/Dearborn's history. Unfortunately there is much documented history of technology being quashed, patents being bought and buried, innovations left by the wayside to discourage change, discourage having to retool, reinvent, reinvest...and if you don't think that auto/oil/gov are all complicit in this, how naive can one be? GM and the railroads, the Tucker, fuel injection, Wankel engine, anti-lock brakes...all quashed by powerful companies and people not wanting change no matter what the benefit would be in safety, society, or the environment.
Review of Who Killed the Electric Car?
