I have not yet seen Wall Street 2, Oliver Stone’s forthcoming sequel to the 1987 drama that introduced us to Michael Douglas’ Gordon Gekko, the reptilian stock-market overlord who coined the unofficial ’80s motto, “Greed is good.” But I cannot imagine a more fitting coda to Gekko’s saga than Brian Koppelman’s story of a down-on-his-luck car dealer nosediving to the nadir of a midlife crisis.

Ben Kalmen, played by Douglas as a cross between Gekko and the more amiably disposed professor he played in Wonder Boys (2000), is not the guy you’d want dating your daughter, your mother or even a casual friend. At the beginning of Solitary Man, he is warned that his body might be failing him; heart tests are in order. Kalmen never follows up. Six-and-a-half years later, he is mired in a quest to recover his youth by sleeping with any woman willing to risk sharing his bed.

Kalmen’s woes aren’t restricted to his heartlessly compulsive womanizing, including the seduction of his girlfriend’s teenage daughter during a college visit to Boston. He drinks to wretched excess. His daughter (Jenna Fischer, of NBC’s The Office) rejects him, though his ex (Susan Sarandon) seems more resigned to his affairs than enraged by them. And, denied a new dealership after deep-sixing his old ones by cooking the books, he’s running out of cash to finance his lifestyle.

I’m tempted to call Solitary Man a belated coming-of-age story, but that would suggest Kalmen learns something along the way. One of the movie’s great strengths, in its convincing portrayal of a man unwilling or unable to put the brakes on his decline, is that Kalmen’s redemption is left as unfinished business. Koppelman, who co-directed with David Levien, offers no facile solutions.

It’s true that the role is no stretch for Douglas, who has played different versions of Kalmen before, but that takes nothing away from his nuanced performance. Kalmen is a lout – his brazen arrogance, boundless selfishness and serial betrayals make that clear. But he is not without charisma. Here, Douglas pulls off a neat trick: He makes Kalmen likable, with a gracefulness the character probably doesn’t deserve.

And yet where would Kalmen be without it? For a movie like Solitary Man to give us some plausible rooting interest, Ben’s unpleasantness has to have limits. (Without them, you’d have a Neil LaBute movie, where his rottenness would be the whole point.) Kalmen is irrepressible, in his own twisted way. He cheats his family and friends, and rationalizes the most deplorable behavior. Yet he does so with such slickness and self-assured candor – he remains an unapologetic salesman at heart – that his shameless spiel almost makes sense.