BMW's 5 Series and Hyundai's Sonata received the highest scores for passenger cars and trucks under a new U.S. crash safety rating system.

The two vehicles were the only ones to receive the top safety score of five stars in crash-safety tests, the National Highway Traffic Safety Administration (NHTSA) said Tuesday. Both vehicles scored four stars in frontal crashes and five stars in side-crashes and rollovers.

The NHTSA tested 34 different models under a new testing regime. And for the first time, female crash-test dummies were used as well as male.

"Through new tests, better crash data, and higher standards, we are making the safety ratings tougher and more meaningful for consumers," Transportation Secretary Ray LaHood said.

The worst performer in this batch was Nissan's Versa, which got an overall score of two stars.