. >> reporter: gm is the car company that produced infamous chevy vegas, x cars in '80s and saturns and plain ugly pontiac aztecs in the 2000s, that's why the post bailout strategy is to improve reliability and its reputation. with more and more extreme testing. first up, wicked weather. every car on the assembly line endures the water test booth. when i psh this button? sxwlt torrent will begin. >> reporter: here we go. our car disappears as it's pelted with nearly 7,000 gallons in eight minutes. so it's not just about keeping the passengers dry but also the engine dry? >> passengers are almost secondary. >> reporter: not surprisingly, we stayed dry. gm didn't show us any cars that might actually fail a test. water falling is one threat. water rising is another. >> we've only been doing this\the last couple of weeks, actually. >> reporter: this water trough tests the car's ability to keep passengers safe in floodwater. it seems like you're testing not only for what you want people to do with the cars but for what they'll actually do. >> it's the extreme. the vehicle has to be shown tha