It shows how to build a teardrop trailer chassis (base or foundation) at home without the need for welding.
Chassis styles include a lightweight version, a comfort version, and an orthotic version for players with special needs.
The throttle and exhaust are part of the engine system, the brakes and steering are part of the chassis, and of course the shifting is part of the transmission system.
Everything else in newer cars are additional things, but to build a car, all you basically need is a motor, a transmission, and a chassis.
The same year models also had problems with the engine control sensor, as well as loud engine noise due to the 4-cylinder engine being underpowered for the size and weight of the chassis.