In 1970, Cadillac first offered a power sunroof on selected models. Up until that time, sunroofs on American cars had been rather limited. It was available on the Thunderbird in 1960, and I imagine there were other instances, but by and large it was not common.
Today, sunroofs are no big deal. Heck, you can get them on just about any 2018-19 model, from a Civic to a Rolls. But back in the early ’70s, they tended to be limited to premium European cars. Mercedes-Benz, BMW, Jaguar and the like.