Tesla roof so strong it broke crush-test machine: USA Today
http://www.usatoday.com/story/money/cars/2013/08/20/tesla-model-s-crash-test/2678557/
As crash-test boasts go, Tesla is claiming a good one: The roof of its Model S electric sedan is apparently so strong that it broke a testing machine during independent validation of its government crash-test scores.
Roof-crush strength was just one of the reasons that Tesla says its electric car just came up with a five-star rating in National Highway Traffic Safety Administration testing.
Five stars is NHTSA's top rating. While other plug-in electric models have overall five-star ratings, a perfect five for each of the three test scores is relatively rare. The 2014 Ford Focus electric also is rated five stars overall and in side-crash testing, but four in rollover and frontal-crash testing. The 2014 Chevrolet Volt is rated five stars overall but has a four in frontal-crash testing. Nissan Leaf is rated four stars overall