According to the seller, the car has undergone two years of research and development work, including 40 different sets of wheels, tires and driveline parts. Additionally, the weight was reduced by about 300 pounds. These modifications have paid off with a claimed average fuel economy of 50 miles per gallon. That's quite a leap over what the stock 3.0L V6 engine was able to manage from the factory, but there's absolutely zero outside verification of this figure.
Wired did a little digging and found that the force behind BrocktonEnergyLLC may be Paul Zigouras, a man that claims to have invented something called a hydroxy gas electrolyzer system. We're not touching this one with a ten foot pole, so feel free to draw your own conclusions as to what's going on with this particular LeBaron. Interested? Bidding has thus far reached $1,900.
UPDATE: This is apparently not an ex-X-Prize car. Just hype.
[Source: eBay via Wired]