Ford (NYSE: F) is continuing its partnership with Westport Innovations (NASDAQ: WPRT) in expanding its offering of its Super Duty line to more trucks featuring Westport's WiNG System, which uses compressed natural gas (CNG) first, then gasoline once empty. The offering will be primarily for fleet vehicles rather than individuals, but the system has received critical acclaim and shows that the auto industry trend's more toward CNG is continuing. In this video, Motley Fool industrials analyst Blake Bos gives us more examples of this trend and tells investors what to watch, and how they can be a part of it.