cartechboy writes: We are all aware of the Tesla Model S fires that have occurred, and that includes NHTSA. A while back, NHTSA opened an investigation into the fires to see if there was a safety defect in the Model S' design, now it has decided to close the investigation. The safety association is quick to note that by closing the investigation does not constitute as a finding in regards to a safety-related defect, and it reserves the right to take further actions if it deems necessary in the future. The fact that Tesla issued a software update that revised the vehicle's ride height, and has also developed a titanium battery shield, hollow round aluminum bar, and a shallow-angle solid-aluminum extrusion. Combined, these three things should help protect the battery and Model S from road debris and prevent battery packs from being damaged leading to fires. This satisfies NHTSA, but will it put the public's mind at ease? That's yet to be seen.