What is the reason for the bulge in the middle of the rear seat of a car?
2 Answers
Below are the reasons why there is a bulge in the rear seat of a car: 1. To increase the height between the car chassis and the ground, because the chassis of a family car cannot be too close to the ground, which would threaten driving safety. In the early days of German car manufacturing, a beam structure was used, and the most important feature of this structure is that it can ensure the integrity of the car body in a collision. 2. To protect and arrange the exhaust pipe and drive shaft, the rear seat of the car needs to have a certain bulge. The exhaust pipe and drive shaft need to pass through the middle of the chassis, so a groove must be designed to arrange the drive shaft and exhaust pipe. The design of the groove strengthens the hardness of the chassis and improves the overall safety of the vehicle. 3. Cars with a bulge in the middle of the rear seat have relatively higher body strength than flat-bottomed cars, which is considered for safety to protect the lives of passengers.
I've noticed that the hump in the middle of the car's rear seat is most commonly due to the need to accommodate the driveshaft or exhaust pipe underneath the chassis. My family has owned several cars, especially rear-wheel-drive ones, where this hump is particularly noticeable. This is because there must be a driveshaft running from the engine to the rear wheels, passing directly beneath the seats. Without this design, there would be no place for the driveshaft, and the car wouldn't move. Additionally, some models have this hump to reinforce the chassis, improving overall torsional rigidity and reducing body roll during turns. While it slightly affects the comfort of the middle rear seat—making it feel like sitting on a small saddle—you get used to it over time. When buying a new car, I recommend checking the specifications and opting for front-wheel-drive models, as their humps are usually lower, offering more spacious interiors.
