Luxury sport coupes and convertibles have always been an important part of Jaguar’s product lineup, and this new 2007 XK is a big step toward the continuation of that tradition. The most significant change to the new XK has to be the all-aluminum monocoque structure, engineering that first debuted on the current XJ sedan. No other car in this segment offers this technology. The use of the aluminum structure results in overall weight savings and a body shell that is 31-percent stiffer than the previous steel skin. Weighing in at 3,671 pounds, the 2007 Jaguar XK isn’t exactly lightweight but sheds 108 lbs. compared to the current XK Coupe.