As others have stated, Cadillac fell in prominence in the early 70's, and it was obvious to car fans at the time that the accountants at GM had taken over from the engineers. It was a brand that went from cutting edge styling and design to a collection of rebranded cheap Oldsmobiles and Chevrolets. I vividly remember a friend's dad throw an absolute fit when the vinyl roof of his new Cadillac pulled away from its trim, and he found an Oldsmobile badge underneath.

Cheap materials, slab sided poorly fit body panels, plastic hub caps painted to look like wire wheels. A few people who were non-car-people would continue to buy them, but most people moved on to Mercedes who had built up a solid reputation at the time. When the Cadillac Cimarron was introduced, even the non-car-people started to recognize what was happening.

The entire brand was at risk of being closed (like Oldsmobile, Pontiac, and soon to be Buick), until one rebadged vehicle became their greatest modern hit. GM rebadged the Chevrolet Tahoe as the Cadillac Escalade, and it was a huge success.

Along the way, Cadillac tried to extend the success to their passenger car line over the last 20 years by pursuing BMW customers. Gone are the floaty pillow cars Cadillac was known for, replaced by German inspired sports sedans. While they have had some success with the niche performance models, BMW fans were not going to switch. Also, Cadillac alienated what remaining customer base they had left who didn't want a stiff ride, low slung car.

Anyway, I'm old enough and been a car fan long enough to see the same patterns happen to other companies. Mercedes was peak engineering in the 70's and 80's. They would take a new car off the assembly line and put it on a track, run 50 or 100,000 miles straight, and learn what could be improved. Models from that era can be found all over the world in 3rd world countries still running as if they will never die. When Mercedes announced to investors in the 90's that they were going to become a "fashion brand," I knew it was over.

Lexus and Infinity came along in 1989, and instantly took a huge share of the luxury automotive market (mostly Lexus). Of course the LS400 from that era is still known as a million mile car.

BMW in the late 90's made a hard push to make their vehicles more reliable, and it worked, but everything went sideways in the late 2000's and have never returned to greatness.

This is making me sit and think about what "luxury" brand I would own now. Most of the high end brands are now confusing technology for engineering and I simply don't like any of them. The truck I bought for towing is very comfortable for long trips, has plenty of room front and back (what large cars had in the past), no computer menus to dig through just to turn on the headlights, and a full size spare tire so I don't have to call roadside assistance in a place with no cell service. Even my beloved 911 has become insufferable over the last few years.

Anyway, if you made it this far, thanks for hearing out the ramblings of a car guy who now feels old.