iss and Kill (1969)

The nice-guy blues
The nice mild man named Edward Tollman had a problem. His lovely wife was missing, and he wanted her back -- fast. So he went to a fellow whose specialty was solving problems like that -- a very private detective called Barney Burgess. Burgess' methods were not pleasant -- but they got results. Burgess was used to sordid scenes and secrets. But after four quick corpses, a wild ride to Mexico, and a blonde sex bomb who threatened to blow the case wide open at the first wrong move, Barney began to wonder how such a nice guy got him into something this nasty... .

Ghostwritten by Charles W. Runyon his third and last contribution to the series. (Death & Ghosts F.Nevins 1998). A tornado-paced fable of pursuit and menace complete with sex, sadism, machismo and a psychopathic monster. When a young Chicago housewife vanishes after returning from a solo tour of Mexico, her distraught husband and a local PI take up the trail and soon discover that everyone else on that tour has either disappeared or suffered a violent death.
About halfway through the book the action shifts to south of the border where Runyon had spent many years, and the two urban male protagonists, joined by a woman photographer from St. Louis, become instant experts at guerrilla warfare against professional killers. But neither this implausible development nor the recycling of tough guy fiction’s most overused climactic “surprise” diminishes the pure headlong storytelling drive that makes Runyon’s ultimate men’s-mag adventure impossible to put down unfinished. (Nevins)

We also like to mention the existence of a 1960 unrelated book with the same title  ... Kiss and Kill by that other ghostwriter Richard Deming. The cover text reads: "Here was a deadly version of the worlds oldest profession". To be clear, Deming himself said in an interview to have written 10 books under the Queen-monicker and all are already accounted for, so this is just coincidence ... 

Right: Kiss and Kill - Richard Deming in 1960