At a local swapmeet a couple months back i picked up these two prints. the man i purchased them from told me he got them from a friend who worked at a gm plant in the 60's, they seem to be in original frames and they have huge magnets all over the back, possibly they were hung somewhere on metal? I looked up the artist Syd Mead and found he was a conceptual artist for alot of car company's and some movies like Blade runner and Tron. I found pictures online of similar prints to the one with the black car and sphere, but i cant find any info on the one with the futuristic semi trucks. Any info on these? are they even GM? Most of what i have read about Mead it seemed like he did most of his work for fomoco.
http://sydmead.com/v/11/ Don't know if he was contracted by GM though. The only automobile manufacturer I saw he worked for was Ford in 1959. Since he did design work for "Blade Runner" I am sure he worked with Gene Winfield for construction of the "vehicles" for that film.