Watching Cars Get Assembled Helps Visualize How Spectacularly Complex They Are

You probably already know how complicated a modern car is. Sure, you may not like certain things about modern cars, but there's no denying the effort it takes to push a new car out the factory door. Nothing about car design and development is easy, and manufacturing is no different. It's a harmonious display of both human ingenuity and controlled chaos.

Distilling things down to the basics reveals that car manufacturing is a five-step process. It starts with stamping all the metal parts, then welding the important bits, and painting the whole thing. The semi-finished shell then comes to life, as everything from the wiring harness and interior upholstery to the engine, brakes, and tires is assembled in a complicated yet delicate dance. And the finished car ends up in the inspection bay before it leaves the factory.

To understand the depth of the process, we'll take a look at a video by English YouTuber Joe Achilles of a BMW M3 Touring being built. It starts as a bare body shell made up of 400 parts and panels, held together by 6,000 spot welds. As the shell moves along the production line, it reaches a point where the front and rear doors are removed, after which some of the rubber seals and soundproofing are installed. Not long after, a massive bag full of wires and connectors — the nervous system that communicates with the many computers inside the car — is introduced, and several workers get busy routing the wiring loom through the many nooks and crannies of the Touring's bodywork.

At the next stage of the production line, the M3 Touring is placed inside a jig that rotates to allow workers access to the car's underside, where they can install the fuel tank and heat shielding. Parts of the interior, including the roof liner, speakers, and carpets, are installed, followed by the pedal box and seat belts. Next, a partially assembled dashboard arrives, and a worker carries it into the car with some robotic assistance. The rear windshield gets installed not long afterward. Meanwhile, a technician jumps inside the cabin to get the center console in place.

The video takes a pause and resumes after the Touring's rear seats and rear-quarter glass are installed. A worker then installs the pre-assembled doors after the front seats are in place. Now, we get to see the engine, transmission, and subframe assembly go underneath the car in what is called the marriage process. All the connections are then made, including the electronics and coolant lines. There are checks carried out at different points throughout the production line to ensure nothing is misaligned or installed improperly.

We see the M3's front and rear bumpers and headlights installed, followed by many of the underside components, including the exhaust. Once the wheels and tires are in place, it gets a full tank of gas, and the car then heads off to the dyno room for some quality checks. Seeing everything happen in the facility makes you realize and appreciate the complexity and ordered nature of the entire operation, which, in the case of this M3 Touring, is a 40-hour process from start to finish.