As fear mounts over possible radioactive contamination from Japan's severely compromised Fukushima Dai-ichi nuclear power plant, automakers have been trying to reassure car buyers that their vehicles will remain unaffected. The most common assurance offered is that autos are manufactured far enough away from the facility that fallout won't end up on their vehicles.
Nissan, however, is offering consumers more than just words. As an added step to ensure safety, the Japanese automaker…