The Kia plant in West Point, GA offers free tours of its facility. You need to book these in advance and I think they only offer them 1 - 2 times per month.
The tour lasts about 90 minutes. You arrive and get checked in at a visitor processing station. Then they show you videos and have a representative talk to you for 30 - 35 minutes about the plant and their products.
You then boars trams (like the ones at, say, Disney World that shuttle you from the parking area to the main entrance). These take you through a couple of large manufacturing buildings to show you how the cars are assembled.
There is no photography allowed once you are on the trams, understandably.
I thought it was an interesting tour for a perspective on how cars are put together. read more