What would you say about a car that gets 84 miles per gallon, costs only $6,800, and can actually be "free" with some unique financing? There has to be a catch, right?

Well, sort of. But only sort of.

The car is the three-wheeled Elio, from startup Elio Motors. It only seats two, and then only with the passenger directly behind the driver. Also, founder Paul Elio is still lining up funding, and should everything fall into place, the first car would be delivered in late 2016.

When Elio talks about the various segments of the car-buying market, it's easy to see why he's excited. Consider these four segments:

New-car market, with sales of about 17 million expected next year. Used-car market, which is three times larger than the new-car market. "Third-vehicle" market. Most middle- and upper-income households have at least one single-occupant vehicle, also known as an "and" vehicle. "Clunker" market, with 234 million older cars on the road -- and 95 million of them 11 years old or older.

Elio says he won't make much of a dent in the new-car market, but the other three segments can be lucrative. For used cars, the decision may be between a 120,000-mile Civic or a new Elio under warranty for less than $7,000. The third-vehicle market is self-explanatory -- why spend extra on a lot of car when you don't need a lot of car?

The clunker market is where things get interesting, and where the "free" car comes into play. The company wants to offer a unique financing option whereby your gas savings can make your payments. This would allow you -- if you're a qualified buyer -- to drive away in a brand-new car with no money down and a special credit card from Elio. This card must be used to pay for gas purchases, where you'll be charged triple the amount at the pump. So, if you fill the tank for $10, $30 will be charged to the card, and Elio keeps $20.

If you've replaced a clunker that got 27 miles per gallon or less on the highway, your total fuel bill would remain the same (or even go down) while you're paying off the car. (Assuming you drive the same amount with your new Elio.) The reason is simple: With a target of 84 mpg highway and 47 mpg in the city, the Elio will get about three times better mileage than your clunker.

One of the more fascinating aspects to the Elio story is the fact that ordinary folks like you and me can invest in it, even though it's not on the stock market. This is possible through the SEC's new Regulation A+, which provides individuals the opportunity to invest in early-stage companies. This type of investment would be very risky, of course, and you shouldn't invest money in this type of venture that you're not prepared to lose entirely.

Now, how does the Elio get 84 miles per gallon and have a target price of only $6,800? And... what's it like to drive this most unique of vehicles? I was able to take the car for a spin, and get all these questions answered, in the video below. One thing's for sure: If you decide to buy one of these, you'll be very popular!