Buyers of the popular Toyota Prius hybrid, after waiting months to get their cars, are telling dealers to keep them until next month so the buyers can qualify for what's likely to be a much bigger hybrid tax break in 2006. Stating Jan. 1, buyers of gas-electric hybrid vehicles get tax credits that could lower their income tax bills as much as $3,150, according to an analysis by the American Council for an Energy-Efficient Economy.

The IRS hasn't set the amounts, but the size of the credit depends largely on the government's fuel-economy rating of the vehicle in city driving. Prius' 60 mpg city rating makes it likely to qualify for the maximum, the council says.  The 2005 tax break for buying a gas-electric hybrid vehicle is a $2,000 deduction.

That translates to a tax cut of $700 to someone in the 35 percent tax bracket, $560 in the 28 percent tax bracket and $300 in the 15 percent bracket.