Heading into BMW’s factory in Spartanburg, South Carolina, the tour guide asked if it was my first time in a car factory. Errr, no.

Working for Autocar, I’ve spent a fair chunk of time donning ill-fitting high-viz jackets and other safety kit before traipsing through all manner of industrial facilities. The guide nodded, then asked: “Do you ever get bored of them?” I wasn’t being polite when I answered: “Absolutely not.”

Seriously, what’s not to love about a car factory? Car plants are mind-bogglingly complex, vast operations, and no matter how many times you see one, it gives you fresh appreciation for this industry’s brilliance.

Watching a car being assembled by a combination of humans and robots as it ceaselessly snakes its way along a twisting, turning production line is a reminder of how complex such machines are.

It’s always hard to comprehend the scale. You read that Plant Spartanburg produces more than 1500 vehicles per day, but it’s only when you see the size of the factory that you fathom just how many cars that really is.

The main ‘spine’ of the X3 production line at Spartanburg is one mile long, and it branches off at various points along the way. It is vast. And that’s just one of two lines at the plant, which currently covers eight million square feet and employs 11,000 people.

Yet somehow, despite that enormous scale, 1500 times every day the exact parts needed for each car, from massive engines and specific body panels down to the tiniest bolts and screws, arrive in the right place at (just) the right time, down to the millisecond.

It’s also a reminder of how intricate the whole process is. It’s easy to think that designing a car is all sketching grilles and sculpting body panels, but stand in a factory and you’re reminded someone has to work out exactly where each bolt and nut goes and how to fit it all together.

Then you stand there a bit longer and try to fathom how on earth somebody worked out in which order those parts needed to be assembled – and at scale and unfathomable pace.

There’s another reason I never get bored of car factories: they’re all different. Clearly the fundamentals are the same, but you absolutely see corporate and cultural differences in each.

Ferrari has just opened a new ‘e-building’ at Maranello, and even though it’s ultra-modern and filled with natural light, there’s still a hushed, near-devout feel to it. Up the road in Sant’Agata, Lamborghini mechanics crowd round a bench hand-assembling engines, looking more like open-heart surgeons.

Volkswagen’s Wolfsburg plant is all industrial chic and fuelled by currywurst, while in Toyota’s Burnaston facility, pedestrians unfailingly obey the five rules of walking (seriously, it’s a thing). Heck, several years back I visited the Lada factory in Togliatti (a trip unlikely to be repeated any time soon) and genuinely saw a burly Russian welding joints without a top on.

And even if they were all the same, I don’t know how you would ever get tired of watching the relentless, unceasing operation. Car factories definitely aren’t boring. Bring on the next one.