The latest round of rollover testing by the National Highway Traffic Safety Administration (NHTSA) puts the BMW Z4 roadster at the top of the list for rollover performance, and the Volvo XC90 all-wheel-drive SUV at the top for front crash protection. The "star" rankings for both vehicles were five, the highest awarded by the safety agency. Other highly ranked vehicles include the Nissan Murano for rollover protection and the Honda Element 4x4 for frontal impact protection. More results can be seen on the NHTSA Web site, www.nhtsa.dot.gov.