Of the original 97 team entries for the Automotive X Prize, about half are one step closer to winning the grand prize of $10 million.

The competition is an offshoot of the original Ansari X Prize, which awarded the same purse amount to the first team to fly a private aircraft into space (won in 2004 by Burt Rutan, who was backed by Microsoft co-founder Paul Allen). The winner will be the team that best creates a 100-mpg vehicle that is suited to mass production. Among the survivors going into round two -- all of which had to prove to a panel of seven automotive experts that their cars would be ready in time for spring track tests and to provide business plans -- are a handful of big-name entrants. These include the likes of electric-car pioneers Tesla; Tata Motors, the Indian company that owns Land Rover and Jaguar; and Aptera, which is backed by Google.

While much-smaller outfits also are still in the running, the undoubted feel-good story is that of the West Philly Hybrid X Team, a group of high-school students -- yes, you read that right -- led by Simon Hauger, a former math and science teacher. The group is relying heavily on donations and contributions; a professor and graduate student from Philadelphia-based Drexel University are designing the computer control systems for the two vehicles the team is working on. But it's not exactly a Disney-esque underdog story. West Philly Hybrid X Team has already raised $300,000 of its projected $400,000 budget, and is a competition-tested group that took home the top prize in the Tour de Sol alternative-fuel-vehicle contest in both 2005 and 2006.

One movie-worthy wrinkle in the West Philly team's story, though, is the fact that none of the students -- even those of legal driving age -- can operate the vehicles during track test runs. For that, as the competition rules state, you have to be 25 years of age.