If we go back 60 years, here is a list of things that weren’t standard equipment on some cars:
turning signals–I had to add them to my 1947 Pontiac
two tail lights–these weren’t standard on some of the wooden station wagons and not standard on the Jeep station wagon
passenger side windshield wiper–this was an option on the Ford F-1 pickup through at least 1950
heater and defroster–this was an option on most cars. Many buyers went to Sears or Western Auto for an after-market heating and defrosting system
radio–this was most definitely an option
Oil filter–neither my 1947 Pontiac nor my 1955 Pontiac had oil filters. Oil filters were an option on the 1955 and not even available on the 1947
horn–this wasn’t included on the 1949 Dodge Wayfarer roadster
passenger side sun visor–this didn’t come on the lowest trim line models of the Chevrolet
arm rests–these didn’t come on the lowest trim lines
floor mats–most cars had a rubber, permanently installed floor covering. The throw rugs that just caused a Toyota recall weren’t available–maybe we were better off that way
back-up lights–these were a definite option on many cars
By these standards, the 1957 Studebaker Scotsman was a luxury car. It had a recirculating heater, passenger side windshield wiper and turning signals. What more could a person want? Well, here are a couple of standard features that I would add for today’s cars:
LED taillights and front parking/turning signal lights as well as dash lights (when the technology improves, let’s have LED headlights as well)
Oil pressure gauge (we used to have these, but many cars today just have the warning light)
Chair height seats as in the Chrysler products through 1954 and other makes as well. Consumer Reports in a 1992 issue tested the Buick Roadmaster, Oldsmobile 88, Mercury Grand Marquis, etc. and compared these cars with a forty year old 1952 Buick Roadmaster for comparison. One place where the 1992 models lost out in comparison with the old Buick was in seating comfort. I don’t think things have improved much since the 1992 models in the area.