#185 Carol: The Canadian government doesn’t allow low speed “neighborhood electric vehicles” on the hiways, as their maximum speed is only 35 to 40 mph, and they don’t meet the same safety requirements of faster vehicles. Some Canadian cities are allowing NEVs on residential streets with speed limits of 35 mph or less. An electric car capable of freeway speeds and meeting full safety standards are allowed on all roads.

The idea of a swappable battery is a common one. There are some technical details to work out, the batteries would have to be leased from the battery swap company, and it is not entirely clear if the economics works out. Project Better Place is trying to develop a swappable battery pack system, along with public recharge stations.
http://www.projectbetterplace.com/

Rectification is unlikely to “eat” 70% going from AC to DC. Checking Wikipedia under “rectifier”, I find that the peak voltage drop for a silicon diode is 0.7 volts, two diodes in a bridge rectifier would be a 1.4 volt drop. I’m not sure what voltage the Volt will be using, but even at a modest 240 volts AC the rectifier operates at over 99% efficiency, less than 1% loss! Now if you were to rectify a mere 2.8 volts AC, the efficiency is only 50% due to voltage drop, but somehow I don’t think that would be useful to power an electric car! Hmm, maybe you were confusing it with some older less efficient rectifier, but I’m not aware of any that are that inefficient.

The 33% figure you quote from Capstone includes both turbine efficiency and generator efficiency, but not “motor to wheel”, adding that in would drop it to about 31%, still well above the efficiency of a typical non-hybrid.

Now figuring an overall “Tank to Wheel” efficiency comparison between non-hybid petrol cars and electric hybrids gets a bit more complicated. Both types have thermodynamic losses in the IC engine. The electric hybrid has conversion losses not seen in non-hybrids, but series and split path hybrids can take advantage of several energy saving efficiency boosting techniques not available in non-hybrids, such as: Regenerative braking, Engine shutoff/autostart, low speed electric only operation, Atkinson/Miller cycle IC engines, and keeping IC engine speed near optimum regardless of road speed. Also, non-hybrid automatic transmission cars have torque converter losses not found in Series or Split Path hybrids. The result is higher overall efficiency for hybrids, and the real proof is in the on-road performance. It really is possible to get 45 to 55 mpg with reasonably good driving, as more than a few Prius drivers can tell you. While the fuel efficiency of a series hybrid like the Volt may turn out to be slightly less, it will still be well above the efficiency of a non-hybrid.