The biggest question of them all: Volt 2.0 vs. Cadillac ELR. Will the only difference between Volt 2.0 and Cadillac ELR be the two-door vs. four-door body and a fancier leather interior? Or will there be more fundamental drivetrain differences? 1. Yes. GM needs to differentiate these two models, giving the Cadillac a more powerful engine/motor, perhaps even a fancier battery, which would yield longer electric range. 2. No. The cost to develop, test and manufacture two cars with so many differences is too much, especially in a line that's selling under 100,000 units per year. Therefore, the two cars will be identical under the skin. We will soon find out whether (1) or (2) above is right. I think this is close to 50/50, but with a gun to my head my money is on (1) -- material differences under the skin, which admittedly goes against a whole bunch of sound logic. GM is damned if it does and damned if it doesn't on this one. At least the cars will most likely be superb class-leaders either way. At the time of publication the author had no position in any of the stocks mentioned.Follow @antonwahlmanThis article was written by an independent contributor, separate from TheStreet's regular news coverage.