I guess I was lucky...when I got my car, the build sheet was with the owners manual. Guess the previous owner found it, no idea where though. It was a little ripped on the edge otherwise 98% intact.maybe by the 80's they discovered they make more money selling the paper to be recycled
I've heard many people who've found them under the back seats. But yeah theyre a pretty rare find on these carsits not underneath the backseats or in the dash anywhere as i have had both out for work, has to be under the carpets as they are not under the front seats either, but i didnt think they put them in cars anymore