Early 1970s Cadillac El Dorados. Anything from '71 through '76 (last year of the convertibles). Maybe it was the ginormous 500 cubic inch motor. Maybe it was the front wheel drive - so, basically, the entire rear 3/4 of the car was dead weight to the giant engine and front wheels.
No matter how you look at it, the early '70s El Dorado was a definitive piece of American motor.
I will admit to a bit of prejudice here. In my youth, a friend's brother was selling a '74 El Dorado convertible that I was itchin' to buy. Oh, sure, the roof was more duct tape than canvas, and the frame had some rot, and the motor was losing compression, but it was a '74 Cadillac El Dorado, man. Same kind like Boss Hogg had!
When the engine threw a thick cloud of blue smoke, shuddered, and then died before we could even do the test drive, I had to pass on it - and I thought long and hard...
That is all.