5. Mercedes-Benz S-Class (W140)
The Mercedes-Benz S-Class W140, produced from 1991 to 1998, epitomized luxury and innovation. (en.wikipedia.org) It introduced features like double-pane windows for enhanced soundproofing, (topspeed.com) power-assisted closing for doors and trunk lid, (en.wikipedia.org) and self-closing doors. (mbca.org) While these advancements set new standards in automotive comfort, they also added complexity, making maintenance a challenge even for seasoned technicians. (motorbiscuit.com)