GM's big mistake with the Chevy Volt, how would you fix it?

[Trekd]

In the beginning, market studies shows that this car must sell at around $20,000 to be competitive and save GM.

Now the price has ballooned up to $40,000 by the time the car is on the showroom floor.

The Chevy Volt is not a hybrid, but a true electric car with a battery pack and a small gas 1 liter 3-cylinder engine that generates electricity only when the battery pack runs low, also called extended mode. While the car is in extended mode, the engine generates electricity to the electric motors AND charges the batteries. The engine itself is not physically connected to the wheels.

It does not have an engine/transmission drivetrain like any other car, even the Toyoto Prius has the traditional engine/transmission drivetrain (it just has a battery pack added on).

Here's the big mistake: The reason for the high cost increase is the battery technology is still in its early stages and very expensive.

Here's the big question: If the Chevy Volt gets 50 MPG while in extended mode, why not just skip the whole battery technology and make the car with just the gas engine to provide the electricity?
That would put the price well below the $20,000, reduces the weight of the car, adds more interior room, makes it competitive with the Prius, the little engine can be easily replaced if worn, swapped for a better cleaner one, or swapped for a diesel one that can run on biofuels.

The question: What do you think GM should've done?

[junior]

The battery is required to store this electricity, and a generator strong enough to drive the motors at anywhere near the speed required to be safe, would have to be huge and heavy without a storage battery. The engine would therefore need to be much bigger to turn the generator, thus killing the gas mileage benefit.

Diesel freight trains have far larger engines than are necessary to drive the generator for the electric motors. Excess electricity produced by the generators that the motors don't need is routed through resistors on the roof of the engine, turning into heat and dissipated into the air. Trains are built for extreme load carrying, so the extra weight of the oversize engine is negligible.

Eventually, if the demand is there, battery costs will come down. Right now, that just is not the case.

[dingram1]

Use basically the same technology as train dynamos? I am left wondering about the electric motors generating electricity to charge the batteries. A power source can't furnish enough power to replenish itself power and still do another task. In other words it can't power the car and charge the batteries. The Auxiliary gas engine can but that is why it is rated at 50MPG instead of 150?!?
Why not build a car that needs NO batteries for power and let a generator furnish the power?

A hydraulic pump can't furnish enough of pressure to power itself. Hence I say electricity is the same way. A generator can't produce enough of electricity to power itself and the car.