After investigating two fires that consumeda pair of Tesla Model S sedans last year, the National Traffic Safety Administration released a report stating that it hasn't found a "defect trend" that would indicate the electric sedan is unsafe. But that's not stopping Tesla from upgrading the underbody armor of its cars.

According to a statement from NHTSA, "Tesla’s revision of vehicle ride height and addition of increased underbody protection should reduce both the frequency of underbody strikes and the resultant fire risk. A defect trend has not been identified. Accordingly, the investigation is closed."

The two fires in the U.S. started after drivers ran over debris in the road. In one case, a trailer hitch and in the other, an unidentified metal object. In both situations, the objects punctured the lithium-ion battery pack that spans the bottom of the Model S, causing a thermal runaway event that resulted in a fire.

After investigating the events, Tesla Motors sent out an over-the-air update to the Model S sedans on the road that would raise the ride height of the EV at highway speeds, reducing the chances of striking an object on the road. And now Tesla is taking it a step further with a new array of underbody armor.

Tesla CEO and co-founder Elon Musk took to Medium to explain the new triple shield that would "bring this risk down to virtually zero to give Model S owners complete peace of mind."

The new armor starts with a hollow aluminum bar that reduces the force of impact or deflects the object completely. Rather than the object going into the battery, the bar would send it toward the plastic underbody tray and the front trunk liner.

The second shield is a titanium plate–the same grade used in aerospace and military applications–to protect the battery. In the unlikely event that it fails, a third barrier of solid aluminum mounted at a shallow angle will deflect the object and absorb the energy of the impact.

The new armor has been fitted to all Model S sedans manufactured since March 6 and will be available as a free upgrade to current Model S owners. Tesla claims that the new armor won't have any impact on the ride or handling of the Model S, and will result in a 0.1 percent impact on driving range.

Tesla conducted 152 tests of the new shields and, according to Musk, engineers found they "prevented any damage that could cause a fire or penetrate the existing quarter inch of ballistic grade aluminum armor plate that already protects the battery pack."

And just to show off, they've released a few GIFs of the new armor in action. Enjoy the destruction.