ABC revealed Ricky DeRennaux and his "HT Custom Racers" toy product and Greg Chavez and his "Guardian Angel" automatic Christmas tree fire extinguisher kit as the first two finalists for American Inventor's second season grand prize at the conclusion of last night's broadcast of the reality competition show. 

As the winners of the show's Los Angeles and San Francisco audition locations, DeRennaux and Chavez each received $50,000 to continue developing their invention ideas.

DeRennaux's "HT Custom Racers" is a custom toy and computer software kit that lets teenagers design and print origami-like paper cars, boats, and planes that can be outfitted with the small electric motors and transformed into remote-controlled vehicles.

"I am so ready to go to L.A. and finish this thing up!" DeRennaux, a 45-year-old high-school teacher from Oklahoma, told American Inventor host Nick Smith after Smith and DeRennaux's family and friends surprised him in his classroom with the news that he was the competition's Los Angeles finalist.

DeRennaux defeated fellow Los Angeles finalists Michael Every, a paraplegic special education teacher who invented a fully collapsible wheelchair in his garage; and Richard Kopelle, an American Inventor first-season reject who created "My Therapy Buddy," a plush doll that verbally assures its owner that "everything is going to be all right," to claim American Inventor's Los Angeles auditions title.

"Out of all of them for me, I've only got one, 'HT Custom Racers,'" judge Peter Jones said as he and the rest of the judges deliberated about which Los Angeles finalist should get to advance to American Inventor's overall finals.

Chavez's "Guardian Angel" is a still-unproven concept for a Christmas tree fire protection kit that would sit atop Christmas trees.  Should the tree catch fire, a plug in the tree-topping angel ornament would melt and two gallons of water would rain down and extinguish the fire.

"I'm taking Guardian Angel all the way to the top," Chavez, a 43-year-old firefighter and father of six from California, told American Inventor's cameras after Smith and Chavez's family and friends visited his fire station and surprised him with the news he was the competition's San Francisco finalist. "We're gonna win!"

Chavez defeated fellow San Francisco finalists Erica Fand and Shelley Kohan, who created "Fresh Cuts," a fake flowers disposable room deodorizer product; and Milton Butler, who created "Lawn Master," a five-in-one lawnmower attachment tool, to claim American Inventor's San Francisco auditions title.

"For me, there's only one real, true invention in this mix now... the Guardian Angel," said Jones during the judges' San Francisco deliberations. 

One finalist from each of the show's four remaining audition cities -- Chicago, New York, Houston and Tampa --  will join DeRennaux and Chavez in their attempts to be crowned American Inventor 2's champ and take home the $1 million prize. 

American Inventor 2 will continue on Wednesday, June 20 with coverage of the show's New York and Chicago auditions.