There’s no way one could describe D.J. Caruso’s wild, hallucinatory stab at a contemporary film noir as a truly good picture, but in its scuzzy, bleary way it’s perversely enjoyable–an instant classic among guilty pleasures. The old examples of noir were stylistically baroque, of course, but “The Salton Sea” actually outdoes them in the effort to be ostentatiously weird and dreamily atmospheric. Since it’s not in black-and-white, it can’t emulate their exquisite use of light and shade, but Caruso and his virtuoso cinematographer Amir Mokri strive for a suitable color alternative by fashioning shots that are at once woozily unsettling yet crystalline in their clarity, and the effect is both sumptuous and surrealistic. The peculiar beauty of its compositions doesn’t make the picture any more conventionally attractive–certainly viewers stumbling into it expecting a normal, coherent thriller will flee in droves–but if you’re properly forewarned and arrive with an adventurous attitude, you should find it a positive hoot. It’s so far off the wall that it’s not even within sight of it.

Like so many of its genre models, Tony Gayton’s script offers up a plot that’s at times virtually impenetrable. (Remember that even Raymond Chandler couldn’t explain who committed one of the murders in his incredibly complex “The Big Sleep.”) In this case there are twists and false climaxes that even the most observant viewer will probably fail to grasp. What can be said with confidence is that the story centers on a cooly detached addict named Danny (Val Kilmer) who spends his life in the L.A. methamphetamine subculture in tandem with a sweet-natured buddy, Jimmy the Finn (Peter Sarsgaard). But he’s also an informant to a pair of narcs named Morgan (Doug Hutchison) and Garcetti (Anthony LaPaglia): in one memorable sequence, he puts them onto a hop-headed dealer called Bobby (Glenn Plummer, in an extravagantly exaggerated performance), who winds up dead as a result. Danny, moreover, proves much more complicated than he initially seems: he periodically goes into foggy reveries about his idyllic former life with his wife Liz (Chandra West) and ruminates on his prior career as a jazz trumpeter named Tom; and in the present he takes a protective stance toward a dissipated neighbor, Collette (Deborah Kara Unger), who’s regularly abused by her brutal boyfriend Quincy (Luis Guzman). At the same time he’s immersing himself within a coterie of addicts that includes bug-eyed Kujo (Adam Goldberg) and his bevy of oddly decked-out associates (in one memorable scene a juiced-up Kujo lays out a plan for a heist, which is prospectively portrayed for us as a complete foul-up).

The plot thickens further after Danny, learning that he’s been fingered as a snitch, becomes terrified when he notices a strange car stalking him. To get cash to flee L.A., he arranges a big drug buy between a mysterious Oriental who acts like a cowboy (B.D. Wong) and a completely spaced-out supplier called Pooh-Bear (Vincent D’Onofrio)–an enterprise from which he’ll supposedly walk away with a tidy profit himself. It’s at this point that “The Salton Sea” enters really strange turf; suspicion, duplicity, revenge and extreme violence boil up, and in the character of Pooh-Bear the movie takes on a fever-pitch of weirdness. Playing his part with a gusto that in any other cinematic environment would be incredibly over-the-top but here seems only to represent a slightly higher level of outrageousness, D’Onofrio–cackling and snorting through a plastic nose that replaces the one Pooh-Bear lost to excessive cocaine use–abandons every semblance of reality to fashion a figure so grotesque as to resemble a gargoyle on speed. Pooh- Bear delights in threatening the private parts of people whose loyalty he doubts with a caged but very aggressive badger; he rejoices in staging the Kennedy assassination on the grounds of his desert hideout, using remote-control toy cars with pigeons for passengers and his henchman acting the roles of multiple gunmen; he snickers while suggesting that he’s offering the brains of a human victim to a lunchtime guest. D’Onofrio, again having gained ample weight for the part (as he once did for “Full Metal Jacket”) seizes upon every quirk and perversity of the role with an abandon that even Orson Welles (whom the actor once played, in “Ed Wood”) would have envied. (Indeed, the performance that D’Onofrio’s Pooh-Bear most calls to mind is Welles’ as the huge, lumbering, putty-nosed but disintegrating Hank Quinlan in “Touch of Evil”–a picture in its own way as delightfully excessive as this one.) A series of bloody climaxes tie everything up–or at least are supposed to–but you’re likely to be scratching your head over some plot holes even as you’re giggling over the audaciousness of it all while the final credits roll.

The fun of “The Salton Sea” is tempered at bit by Kilmer’s performance as Danny/Tom; the actor rouses himself to occasionally sharp line readings and some bursts of energy, but more often he’s so subdued and lethargic that you wonder whether he’s trying to figure out the plot, too. (It’s difficult to tell whether Kilmer’s designed the performance as a cleverly ironic twist on the standard angst-ridden noir hero or whether it results simply from indolence.) Some of the other players don’t make the best impression, either. Goldberg, for instance, works much too hard at appearing off-kilter, Hutchison and LaPaglia are basically dull, Guzman is below his prime, and Wong doesn’t do much with what could have been a really eye-catching character. The women– Unger and West–are completely disposable, while R. Lee Ermey and Shirley Knight are wasted in a single scene that refers back to the hero’s former life. But there’s sufficient compensation in D’Onofrio’s wickedly funny turn, in Plummer’s outrageous cameo, and–remarkably enough–in Sarsgaard’s lovely rendering of Danny’s unpretentious, goofy buddy. Sarsgaard was utterly credible as the murderous lout in “Boys Don’t Cry,” and here he’s perfectly natural playing a likable schlub who’s sort of a handsomer, sweeter version of the kind of hopped-up guy Steve Zahn often essays. Sarsgaard shows remarkable range and charisma, marking him as a young actor to watch. Technically the picture is a marvelous feast, with Mokri’s bravura camerawork and Thomas Newman’s evocative score interacting beautifully.

All told, the elegance and audacity evident in “The Salton Sea” result in an oddly gripping experience. The picture’s drowsy, hypnotic tone make it seem like a sultry, lurid dream that one awakens from happy to have experienced it, but feeling in serious need of a shower. If that prospect appeals to you, give it a try.