The front seats featured torso airbags and head airbags even on the earliest models, which few contemporary vehicles did in the late 1990s. The basic structure included a robust passenger safety cage, front and rear deformation zones, reinforced door posts and pillars, as well as the "Pendulum B-Pillar", which combined high-strength low-alloy steel at chest and head height with tailored blank steel at the floorpan, designed to direct the crash forces down toward the floor. The design was proven by the Insurance Institute for Highway Safety (IIHS) to protect occupants in side crashes, even without the addition of curtain airbags or rear side airbags. From 2002, ESP (electronic stability control) was included as standard.