Proving that the global economic crisis can't thwart the American entrepreneurial spirit, the South Carolina-based maker of amphibious vehicles is building a three-wheeled plug-in diesel hybrid. According to inventor John Giljam, the vehicle will have an all-electric range of 50 miles before using any liquid fuel. Based on testing of a pure diesel version that achieves more than 65 mpg, Giljam said, "We would be getting 130 to 150 miles to the gallon with the plug-in hybrid model."