A Night at the Operation (A Double Feature Mystery) by Jeffrey Cohen
From the back cover: Most men wouldn't be terribly upset if their ex-wives suddenly vanished. But then, most men aren't Elliot Freed.
Elliot's ex-wife, Sharon, has disappeared and Elliot of course makes finding her his top priority. This starts a chain of events that leads to murder, disappearing corpses, burglary, blackmail, and all sorts of other fun things!
This is the 3rd book in the series, and I think the best one yet. Like the first two books, it includes lots of great classic movie trivia and hysterical one-liners. But there's also some very touching scenes, as well. Add to that a great mystery and you have a book that is well worth the read.