BMWs full-size flagship executive sedan. Typically, BMW introduces much of their innovations first in the vaunted 7 series. It has been deemed a "sports car at the helm and a limousine in the rear". Numerous landmark and breakthrough technologies for the entire automotive industry debut on the 7 series. For example, the groundbreaking and controversial electronic controller iDrive- "I drive", or the worlds first Hydrogen powered production vehicle, have all debuted in the 7 series. The 7-Series Hydrogen, the worlds first luxury performance sedan with hydrogen drive, is fueled by liquid hydrogen and releases only water vapor. Since the infrastructure for refueling a hydrogen internal combustion engine does not currently exist, the V12 engine also runs on gasoline, enabled via a push button system. Numerous engines power the 7 series worldwide. BMW offers diesel, straight 6, V8 and V12 motors, as well as the Alpina tuned supercharged V8. Additionally, the 760Li is also made in a bulletproof version.