Nostalgia "stereo" implies OEM audio equipment included or optional on old Buicks.
It wouldn't be a stretch to put musical tastes in either category.
BTW: I was just listening to my new $2,200 CD player in my '63 Riv in the garage, after listening to my home stereo, and was blown away. The imaging was incredilbe. The soundstage seemed to stretch out 5 ft. beyond the doors; bass was centered up front. And no unwanted vibrations. After I had stripped the interior, I had added mass-dampening material on all metal surfaces and layers of carpet padding, so the environment was sonically better than most think a car interior can be. And with just 6-speakers in the right locations and receiving signals with staggered discrete crossover points, there were no phase cancellations, so stereo sounded like surround and speaker locations sounded invisible-- The soundstaging was front and center, even sub-bass.
I still can't get over how the right equipment, along with proper installation, can make modern car audio an exhilarating experience.
These are some of the issues that can be discussed in 'all-out stereo.'