Looks like the current Chevrolet Impala will be the last one which is a shame considering what an excellent automobile it is. Ugly as hell but very capable.
The current Detroit-Hammtrack assembly plant first opened in 1985.
How "off" are the sales of sedans? Based on production figures from one of the plants targeted for closure, GM’s Hamtramck plant in Detroit, they've produced just 35,000 automobiles in the first half of 2017; down 32 percent over the same time period last year. Typically that plant produces between 200,000 and 300,000 sedans a year.
Sedans can't compete with do it all cross overs like the Honda CRV.
It's not as if "Detroit" is having a bad year either. The problem is folks are just not buying "four doors" anymore. "Four door" sales are down as much as they are because of the meteoric rise in popularity of SUV's; specifically what are referred to as crossovers or "CUV's". These Swiss Army Knife vehicles clobber sedans at practicality and they're perceived to be two door "cool" too. Quite the one-two punch.
I've never been a fan of sedans so I ain't crying about their imminent demise. Good riddance. And while I've never thought of myself as a visionary with regards to anything let alone something as difficult to forecast as the public's taste in automobiles but...if the brake shoe fits I'll wear it.
My family and I have had Chevrolet Tahoes as our primary family vehicle for more than a decade now. We'll never own a sedan again.