Mr. dB said:
Those '58-'97 cars were the product of one continuous line of automotive evolution. They were all front engine, rear wheel drive, live axle cars in a direct line of succession. Even the mid-1980s "monstrosities" were still based on the downsized 1977 Impala/Caprice re-design, which was pretty good for a big American car at the time. They seem to be sturdy enough today to be the #1 choice in hoopties for the sort of people who like to paint them metalflake orange or green and slap 24" spinners on 'em.
When the "bathtub" Caprice Classic was killed after the 1997 model year (I think that was the year...), that line became extinct. It was not replaced. A few years later a facelifted Lumina was given the name "Impala" and the Lumina coupe was re-named "Monte Carlo" in a vain attempt to tap into some sort of Chevrolet legacy. They're not fooling anyone.
And the new SS is silly, cramming a V8 into a front-wheel-drive car.