Well it is marketing and believe it or not they toned it down from what it was when the S was introduced. The cash price is listed right there below to the "marketing" price when you custom build the car.

The federal rebate is real as of today, and so is the gas saving although you need to factor in your own cost of electricity and the estimated price of gas over the next 5 years. So it is fair game IMHO as long as clearly indicated as it is on their website. The way I see it this is no worse than all the fine print fees when you lease a car everywhere else...