Would you drive a car made out of foam? What if it got 100 miles to the gallon and could save lives?

It's called the Spira4u, and it's one of the more curious vehicles that have been competing for the Progressive Insurance Automotive X Prize, a competition to see who can design the best 100-miles-per-gallon car. 

The competition looks like an episode of the Wacky Races cartoon -- with three-wheelers, space-age designs, converted sports cars and sedate sedans using a hodgepodge of technologies and fuels. But the goal is a serious one: $10 million in prize money, not to mention the possibility of reducing our addiction to oil.

The folks behind the foam-wrapped Spira4u have another goal as well: saving lives. According to Spira  founder Lon Ballard, an American working in Thailand, more than half the fatalities on the road in large cities and developing countries are pedestrians and motorcyclists (in Thailand, it's about 88 percent). So the concept behind the Spira4u was to create a safer alternative to motorcycles and scooters for the Asian market -- hence the foam.

"I pursued this foam concept to make a vehicle safer for both occupants and impacted persons," Ballard told FoxNews.com. 

Based on a Kawasaki motorcycle engine and transmission, the car has a honeycomb core surrounded with a fiberglass-composite structure and covered in soft polyurethane foam. It weighs 500 pounds and seats two. Before the competition, the Spira4u also underwent some unconventional testing, including a dip in the ocean (it floats!) and being loaded with a pig carcass and rammed by a truck -- to test its qualifications, of course.

Ballard and his team have been working on the vehicle for two years. "I've worked 60 to 80 hours a week" during that time, Ballard said, and invested about $200,000.

Alas, after making it from an original group of 97 down to a group of 15 finalists, the Spira4u was eliminated from the X Prize competition over the weekend. Ballard says the car was disqualified because it dipped below the 100-mpg mark in city driving, although it managed that on the highway. 

But Spira shouldn't feel too badly: Bigger companies have also gotten the boot, including an entry from India's Tata Motors, which owns Jaguar and Land Rover.

Ballard and his new company aren't giving up. The car will still appear at the X Prize technology demonstration and finale on Sept. 15 in Washington, D.C., and the company is considering design changes. The chemical foam could be made from nontoxic renewable sources such as soybeans, for example. Ballard believes the vehicle could be produced commercially for just $3,000. And if the company can sell 20,000 or more per year, the price could be cut in half.

Meanwhile, the X Prize competition continues. 

The vehicles face more road tests and an evaluation by auto experts before the ultimate winners are announced. Eric Cahill, senior director of the Progressive Automotive X Prize, admits that the prize money ($5 million goes to the winner of the mainstream category with the remaining $5 million to be split between two winners in the alternative class) isn't enough to bring a new alternative-fuel vehicle to market. It takes hundreds of millions of dollars to do that. So ultimately, the goal is to draw attention to new designs and encourage investment.

And Ballard still believes Spira can get its amorphous foam car into production, based on the motto "soft, safe, sexy." Sexy? Well, two out of three ain't bad.

Follow John R. Quain on Twitter @jqontech or find more tech coverage at J-Q.com.

John R. Quain is a personal tech columnist for FoxNews.com. Follow him on Twitter @jqontech or find more tech coverage at J-Q.com.