Are people missing the point about alternative fuel vehicles?

I truly don't understand why so many people talk about the benefits of this or that alternative fuel because petrol / gasoline / oil is becoming depleted and expensive. Isn't it about steel and copper and plastic, too? The vehicles will still have to built in car plants which will use just as much (if not more) energy and natural resources in their building (even electric cars will require the building of large electric motors and batteries instead of petrol engines, for example ). Or will millions of cars be made of bioplastic materials and the world's car plants and power stations be run on renewable energy or biofuel, too? Don't we need a major rethink here? Shouldn't we be talking about how we're going to live in local communities, work locally, grow food locally and generally reduce our reliance on the car? This is a serious question - I hope someone can explain how we're going to actually build these millions of alternative fuel vehicles.
Thanks for all the interesting answers so far. A couple of my thoughts:

1: I live in rural England so perhaps I underestimated the average American city-dweller's need for long-distance transport. However, I saw a prog on TV which said the American city would not survive in a world without abundant cheap energy.
2: It's my personal opinion that hydrogen cars, compressed air cars, etc., are a long, long way off because a whole new fuel delivery system would have to built across the world. Hydrogen is a non-starter at the moment (high pressures involved in production and distribution, it's made from natural gas, etc.) and compressed air - well, even air compressors require energy to drive them, and the energy output will in someways have to be fuelled by the energy input + losses in the compressors, pipelines, etc. Basically, we're back to the energy-of-production-and-distribution problem with new hydrogen and compressed air infrastructures around the world.