Couldn't stand to wait, did a quick Google and it was, indeed, The Hero. There's actually a site devoted to it, which I guess should not surprise me:
http://www.geocities.com/TelevisionCity/Stage/2950/SitCom/Hero.htm
It was your inclusion of the horns on the car that was the tip-off for me.
Back when I still wasn't tall (but working on it), the only copy of
TV Guide that my family would get during the year would be the Fall Preview Issue. I ended up saving them, had a whole collection, although they're long lost now. Pity.
What I remembered was the thing about the horns on the car (part of the series description), and that there was an accompanying photo of a fellow holding a pistol in front of his face. He was holding it under his nose by the barrel, with the grip pointing up, in imitation of a moustache. The fellow had very distinctive eyes, however.
Flash forward. I realized, while der Brucer was trying to find anything he could on the Internet, that the photograph was of Richard Mulligan. Like I say, distinctive eyes. Der B went to IMBD, and there was the title. Almost nothing on the series itself there, so he had to trust my memory.
(Going back over a decade ago, der Brucer would pick me up at a bar/restaurant in Orange County called OZZ before driving us home. Every night, they'd have
Jeopardy on the television over the bar, and every night we'd be calling out the answers faster than the contestants. Of course, we'd cheat and not bother to give the answer in the form of a question.)
