Wow, thinking about the required logistical management to have the right parts at the right time for that particular car must have been tough! Not to mention training of the employees on assembling different cars.
It's not that hard.
They had an order that the cars were going to go through. The sections would line up parts in that order.
The line worker has very few tasks. Grab the part presented in order and install part. The variation from car to car is not that great. There was probably a verification step for more complicated assemblies like steering columns.
