Porsche adds two new versions of its venerable 911 sports car for the 2007 model year. They are the 911 Targa 4/Targa 4S and the GT3. The Targa features an all-glass roof system that provides a panoramic view even when the top is “closed.” For the first time, this roof is mounted on the four-wheel-drive (4WD) version of the 911, thus the “4” designation. Compared to the Targa 4, the Targa 4S gets a more powerful engine and other performance enhancements. Meanwhile, the 911 GT3 is a particularly racy road car designed for driving enthusiasts who participate in weekend “track day” competitive events but who also want to drive their cars during the week as well.