We didn’t believe it until we verified it with our own eyes, but amazingly it’s true: Colorado is offering a $42,083 rebate on the 2009 Tesla Roadster until December 31st. Carry the one, move the decimal point… yep, that’s a 38-percent discount on what must be the most desirable electric car currently for sale in the United States.

So, exactly how did this come about? Is the thin air that’s distorting people’s better judgment? Not exactly. The incentive actually applies to a slew of qualifying hybrid and electric vehicles and will be paid in the form of an income tax credit that’s calculated by determining the difference in price of the alt-fuel car or truck as compared to a competitive gas-powered model. In the case of the Tesla Roadster, Colorado figures the EV costs a whopping $50K more than its competitive set… which we imagine might be the Lotus Elise.

Want to take advantage of the rebate but not interested in a fully-electric sportscar? Buyers can also get a $20K rebate on the 2009 Lexus LS 600h L or about three grand on either the new Honda Insight or Toyota Prius. See the complete list in PDF form here.