It looks like you have numbers to back up your position, but could that only account for the direct employees of the auto companies? I grew up in detroit. Some people worked directly for an auto company, but the majority worked for suppliers to the automotive companies. Again, I have not looked up current stats, but more than half the families I knew were employed by automotive suppliers. 12% sounds about right for direct employees. Having lived in detroit and san diego, my opinion is that the automotive hit in detroit would be more severe than the aerospace hit san diego took in the early 90’s.
I also know bloomfield hills quite well. 130k is a very low price, even back in the 80’s. I’m not sure where that guy lived, but it was common for home prices to be well above 1M.