The NHTSA stars are adequate for their intended purpose - showing how well a car holds up in a crash compared to equivalent cars from other manufacturers. You j

The NHTSA stars are adequate for their intended purpose - showing how well a car holds up in a crash compared to equivalent cars from other manufacturers. You just can't use them to make any conclusion about the overall risk of injury (which depends on the likelihood of a crash happening in the first place), can't compare them between cars of different weight classes, and can't draw meaningful conclusions about the relative safety of different five-star rated cars. Tesla did all three. The last one might need a little elaboration. The NHTSA battery of tests is relatively small and limited. The lower the risk of injury in those tests is, the more dependent the actual real-world risk becomes on all the scenarios they didn't test. This isn't a hypothetical problem. The Model S also got the best score ever in the NHTSA tests and Tesla did a similar press release about that, but it didn't get the IIHS's highest rating because it performed badly in small-overlap collisions which weren't part of the NHTSA tests.