Tesla is trumpeting the Model S' excellent performance in NHTSA's safety tests. Tesla says that the model S has achieved a combined rating of "5.4 stars":
Palo Alto, CA — Independent testing by the National Highway Traffic Safety Administration (NHTSA) has awarded the Tesla Model S a 5-star safety rating, not just overall, but in every subcategory without exception. Approximately one percent of all cars tested by the federal government achieve 5 stars across the board. NHTSA does not publish a star rating above 5, however safety levels better than 5 stars are captured in the overall Vehicle Safety Score (VSS) provided to manufacturers, where the Model S achieved a new combined record of 5.4 stars.
This is very odd publicity, to me. NHTSA awards star ratings as integers, and 5 stars is the most you can get. A 5 star rating means that you have less than a 10% chance of serious injury in a serious accident, according to NHTSA's statistical model.
You can't get more than 5 stars, awarded by NHTSA.
Tesla is just trying too hard, here, I think. A 5-star result is excellent, and they should proudly publicize it.