Starring Ryan Gosling. Rated 14A.

The trailers for the noir spoof emphasize the action part of the deal, but it’s really the comedy that matters in the pop-culture nihilism of The Nice Guys.

Meekly mustachioed Ryan Gosling and a Russell Crowe slowly morphing into John Goodman make consistently amusing anti-buddies as Holland March and Jackson Healy, respectively—two private dicks from opposite sides of 1977 Los Angeles. We know it’s the ’70s because the flick hits many of the same notes as Boogie Nights: the cartoonish typography; the leisure-suit-based fashions; the chock-it-a-wah guitars; and, most of all, the wised-up banter by guys who thought they were on top of things at the time but look pretty naïve from this distance.

Gosling’s more polished March has delusions of Raymond Chandler grandeur. But to keep his potty-mouthed 13-year-old daughter, Holly—Australia’s movie-stealing Angourie Rice—in their Hollywood Hills rental, he takes jobs from old ladies too potty to realize their mates are dead, not missing. One seemingly past-it gal (genuine ’70s star Lois Smith) pays him to locate her absent niece, seemingly caught in the porn trade; this puts him in the path of Crowe’s hard-bitten Healey, hired muscle paid by the same niece (cast low point Margaret Qualley) to keep people from finding her.

Several bone-popping altercations later, they realize the case is fishy enough to require both their (questionable) talents—for at least the first half of this shaggy, two-hour tale from writer-director Shane Black, best known for Kiss Kiss Bang Bang and his scripts for the Lethal Weapon movies. The gat-packing gents here might not be too old for this shit, but they are savvy to all the Altman and Polanski updates on California noir, and their dialogue pops with that insight. Plus, Black even reunites Crowe with his L.A. Confidential co-star Kim Basinger.

Sadly, once the latter’s part of the plot kicks in—something vaguely about air pollution and the auto industry—this neon-lit retrotacular loses its casually hilarious edge. And events resolve in the kind of shoot-’em-up set piece that, while still cruel good fun, might be getting too old for us.