"Mother Earth News" magazine published an article sometime around 1980 about a hybrid electric car project. The author had coverted an Opel GT (looks like a Corvette that shrank in the carwash) to hybrid power. It worked.

It's one thing for a good tinkerer to make a single hybrid electric car. It's a far different matter to develop a car for mass production that can be sold economically and make a profit and meet all of the federal requirements for emissions, crash worthiness, safety, etc. Like I said before, I've read that Honda is losing thousands of dollars on every Insight they sell. Until the cost of production comes down and without subsidizies, hybrid cars will not be big players in the auto industry.

A fuel cell electric vehicle would be a better long term solution but they're still a few years away. Right now, the cost of the fuel cells is still too high but they're making good progress. Most people don't realize how much electricity is needed to power a car. One horsepower = 746 watts at 100% conversion efficiency. Given normal losses, you'd need closer to 1 kilowatt per horsepower. To power even a fairly small car, you'll need anywhere from 50 to 100 kilowatts of electricity. You could get by with less if you're talking about a really small and lightweight car but even subcompacts typically have engines over 75 HP.