The "Trivia" page on IMDb claims the filmmakers protested because this film was re-cut by the studio to "simplify the plot". If so, that effort was a total failure, as this is one of the most incoherent narratives I've ever seen in a film -- I'd hate to have seen it before the plot was "simplified."
It's sad to see Warren with so little character to go on that even he can't do anything with the inept material. It's interesting to see Caron in '70s mode instead of her Hollywood-era glamour garb and persona, but it's sad to see her haplessly wander through this doing-a- favor-to-her-producer-husband dreck. She would actually later hook up with and marry the director, instead -- who, you'll note, never directed anything again, but did strictly 1st or 2nd A.D. work in TV from here on out. That oughta tell you enough right there.
I call this "interesting" because I have an automatic fondness for American films of this period, and this role does add perspective to Oates' otherwise fantastic 1971 output (Two- Lane Blacktop, The Hired Hand). But the "1940s detective as fish-out-of-water in 1970s L.A." theme, which is the only thing the movie really has to say, is sold in way too heavy- handed a manner. A similar theme would be far more effectively handled two years later in Altman's The Long Goodbye. And as far as Oates playing a hard-bitten guy on a doomed errand, three years on, he would give his definitive performance in Bring Me the Head of Alfredo Garcia. If you haven't seen those, don't waste your time with this!