During last year's hysteria about gas prices, Clark said it was a bad idea to buy a hybrid. Even at $4.11/gallon, the payback on hybrids simply did not make sense. In addition, dealers were doing what the marketplace allowed at the time and charging far above sticker price.

Now that the price of gas is back down, sales of hybrids have fallen by two-thirds. The Chicago Tribune found that the average supply of Priuses was at 2 days last year. Now it's sitting at 80 days! Keep in mind that a 55-day supply of vehicles on dealer lots is typically where supply and demand are at equilibrium.

The Chicago Tribune is also reporting some people have bought Priuses for $5,000 below MSRP, even though dealers are still pricing them high.

In another example of the declining demand, Chevy Malibu has a hybrid version that's priced above the gas engine model. But they sell less than 100 per month!

Meanwhile, Honda's new Insight hybrid is the first hybrid to be priced in the teens with a $19,800 list price.

The real opportunity, however, is not buying a hybrid new; it's buying one used. A lot of people who got caught up in the hybrid craze last year have discovered they don't exactly love driving around in a "putt-putt mobile."

So now may be the time to strike. Gas won't always be this cheap…