I still say it wouldn't take long to tighten 4 bolts per seat, slide the radio of choice into a double din slot, and attach the dash harness and clip it in. Done. Just that alone would make manufacturing much more simple (cost effective)... 3 radio's x 3 seat choices x 2 dash choices (gotta keep the well loved Elgin in there) x 2 transmissions x 7 colors = 252 combinations that the factory would have to maintain... not to mention that there is NO WAY to build a car with NO notice and then ship it 2,000 miles without hella transportation costs. I believe the trucks spent about a day on the line including the paint booth. Let the dealer slip in the radio, clip in the dash, and put your seats in... the dealer could have 14 cars, 3 sets of seats, radio's, and dashes and be able to have your car ready within 48 hours easily-no matter which of the 252 combinations you picked. Shoot, if it was a slow day, they could have it to you in an hour or so(coffee breaks, naps, etc.). Every task I've listed was performed in 52 seconds or less at the GM plant. I know this first hand. I was an industrial engineer there and my job was to ensure each work station had fewer than 52 seconds per the GM standard time tables. Of course, they had a lifting jig for the seats but other than that, all these parts were quick installs that took literally one repetition before you could do it yourself.
Why is it so hard to think a dealer couldn't do it?... Though, I'll be honest and admit I've been to some dealers where I'm surprised they knew the difference between a manual and automatic transmission.
...And that's the way the cookie crumbles.
So you don't think the scenario in post #27 is possible? Remember, I think only five people work at each showroom. Will each showroom be required to maintain a warehouse in the back to store all of the inventory and pay taxes in January for all the items not sold. Inventory control is an 8 hour job in it's self, so now you are down to four working the floor and lot, minus the ones working on options. If your showroom is open longer, you will have to pay overtime or have some one come in early or stay late which means you will not have five employees on site during the extra hours of operation, not to mention someone calling in sick. The showroom is not there to make money, that is why they all get paid by the hour and there is no haggling.
Every car you assemble that comes off the line that requires an option, and that option is not installed, will become WIP. Not only will it be WIP (not good), it will be placed in a batch and queue situation (not good). All batch and queue situations require storage space, and space equals money (not good). You will be going from single line manufacturing where JIT warehousing is available, to technically requiring a line for each car where ever they end up after delivery. JMO
You being an industrial engineer, I know you know what I'm talking about. I don't have near the training you have. Just in Six Sigma, Root cause analysis, work cell and station optimization, Kaizen and a few other things I Picked up in my twenty years of manufacturing experience. I'm sure there may be some things I'm missing.
P.S. When I started this post, posts 38,39 and 40 were not posted yet.