There's no date on this piece, but my guess would be that it's from the mid- to late 1970's, possibly the early 1980's. It's one of my rare all-color pieces.
If memory serves, this one was inspired by photos of a cool "spherical car" I saw in either POPULAR MECHANICS or POPULAR SCIENCE. I just thought it looked totally "sci-fi". My apologies for the poor quality of the photo. -- PL