It seems that our mystery ship appeared in a series of ads for the 1978 Ford Fairmont Futura Automobile. In retrospect; this was unfair to my UK readers and friends. For that I most certainly apologize. I have no idea how nice or popular the Futura was for the time, but the ship is quite nice. Given its apparent small size and overall structure; it's very likely a surface to orbit personnel craft. One of the ads I'm posting here displays the ship's portside profile revealing a cluster of engine bells at the rear. This rules out FTL or even typical sublight propulsion. She must use solid rocket fuel given the flame spewing VTOL engines employed at the end of the commercial; a real gas guzzler from the look of it. She looks to me like a craft from the same manufacturer as the Icarus from the original Planet of the Apes film series.
Below I've post the two print ads that I'm aware of as well as the television advert. As for the clue I gave yesterday, I'd like to explain it. When I was a kid there was an old joke about the Ford Motor Company. Ford stands for Found On Roadside Dead. That or Fix Or Repair Daily. Old jokes to be sure. Thanks for all the great comments.