Buick Brand Cassette?

I'm doing a little research into the history of the Buick brand and I'm hoping you all might be able to help me track down an artifact.

I've been told that in the 70's, new Buicks came equipped with an audio tape describing the car's features - possibly with an emphasis on safety features. Does this sound right? If so, does anyone know how I could get my hands on one of these tapes?

I'm hoping that these tapes were distributed at the car maker level and that I'll find that there are thousands of them in existence -- my fear is that they were distributed by a few or even just one dealer and they may be very hard to find.

Thanks very much for your help!