At Mercedes-Benz we offer factory tours you can just sign up for. Agree with OP, well worth it!

Developing and iteratively refining a production line from pilot factory to network scale is not entirely unlike software development.

Here's a few clips of a modern one, including a longer doc:

https://youtu.be/UdDvDKC8FVM & https://youtu.be/TWLyRQbvr6o

You can tour the Ford River Rouge truck factory, which is where they make the F-150 and F-150 Lightning:

https://www.thehenryford.org/visit/ford-rouge-factory-tour/h...

I went on a tour of the VW Dresden factory back when it produced the Phaeton and Bentley Continental. It looks like they currently produce the ID.3 there and are still doing tours:

https://www.glaesernemanufaktur.de/en/your-visit/our-tours.h...

I believe Volkswagen's Wolfsburg factory is open for tours

Anyone can sign up for the Porsche factory in Stuttgart, Germany or the MINI plant in Oxford UK, there are probably many others too. Stuttgart is really dominated by Porsche and Mercedes-Benz, there's an giant M-B star on the town's big clock tower. It's a very business-y town but a nice visit for a car nut.

While I was an exchange student in Germany, my cohort got a tour of an Audi factory.

That was 23 years ago, though.