Four speakers? Try ONE speaker in my 1973 Pontiac Grand Ville and it was the top of the line model! It still has the factory AM radio, but being a old, all-original car, I want to keep it that way. FM radio was an option in this car, but my car lacked it. In fact, even AM radio was optional back then. The "FM" option added two rear speakers and dual front speakers, but one in the front center of the dash only with the "AM" radio. If you really wanted to go all out- you could even get the tape player option- yeah, it was an 8-track! The 70s! It does have a lot of other options though, just FM was not one of them. I have seem loaded models lack the FM radio, but bare optioned models with the option. Back in the 60s and 70s, you basically got what option you wanted. You did not have to get "option packages" back then. Pretty neat when you start looking at the old 60s and 70s cars- especially General Motors cars.

My 69' Caprice has FM radio option and three speakers it also has the rare power door lock option, as well as power windows, tilt wheel, A/C, vinyl top, power disc brakes (yeah, they were optional in 69'), hideaway headlights w/washers, 396 engine, turbo automatic, lights group option, etc. Still, a lot of options it lacks.