Audi of American announced that its redesigned 2009 Audi A4 luxury sport sedan earned the U.S. government's highest crashworthiness and rollover safety rating.

The National Highway Traffic Safety Administration said the A4 achieved the coveted 5-Star designation based on its performance in the New Car Assessment Program, or NCAP. U.S. law requires all passenger cars to pass a 30 mph frontal crash test and a 33.5 mph side crash test, but tests are conducted at five mph above the required speed.

The 2009 Audi A4 officially went on sale to American buyers in late September. The A4 offers advanced safety features and accident-prevention technologies in addition to a significantly stiffer and smoother body shell to protect motorists and passengers.

Key safety features include: front, side and side-curtain airbags, an available dynamic steering system that helps stabilize the vehicle and available Adaptive cruise control that detects the distance of the vehicle ahead and slows down accordingly.