That's one of Billy M's concepts I've not seen before - and I thought I knew it all
He had some fabulous concepts, but I cannot say this is a top one. In 1977 when he retired there was a retrospective at the NY Auto Show - these was a 76 or 77 concept car with a periscope rear view feature - the Mulsanne.
My buddies Fazoole and Peckerhead prevented me getting "more better" shots of the fabulous concept Corvettes.
http://www.oosoez.com/dr-r-web/currentevents-45.html
We took the train to NYC Grand Central that day, and we'll never forget this old woman in her 70's sitting in the train station across from us with he dress high & no under britches - we still laugh about it.