Most cars back then only had AM radios.
Right. My '75 Monza only had AM even available.
You had to move up to a Caprice to even be able to get an FM option, up until the full-sizes like Riviera and Olds Toronados and 98's.
I think it was only "standard" on Cadillacs.
I was amazed a couple of years back when one of our members reported a '73(?) Buick Apollo (Chevy Nova clone) that actually had
no radio at all. (In a
Buick?!?, I asked)
He explained that it was a "fleet" model, like a barebones stripper to be modified for taxi or city employee type duty.
Think it was even a 3-speed manual .
But you could buy one for yourself if you wanted.
First car I ever had with standard AM/FM was an '80 RX-7.
But I think my buddy's dad's '74 Mustang II Ghia had it.
Seem to recall cruising while tuned to the local underground FM stations in that one.
I'm sure it was an option, though.