With new rules and revised CAFE standards, the days of powerful, fuel-thirsty cars may soon be long gone There's only one thing to say about a Corvette that can top 200 mph, or a Cadillac sedan that makes the muscle cars of the '60s seem like a bunch of wimps: Enjoy it while it lasts. This golden age of horsepower may be coming to an end, at least in the gas-guzzling manner to which we've become accustomed. -snip- New rules will force the car kings to shift their focus. Revised CAFE standards require automakers to raise the average mileage of...