Veteran TV writer Paul Haggisí second directorial effort is an ambitious mess. A kaleidoscope of slowly interwoven vignettes over the course of a single day and netting a Magnolia-sized cast of Los Angelenos of various social and ethnic stripes, Crash unfolds in scenes of banal beauty, maudlin sermonizing, and contrived twists that keep every character opaque and capable of anything. African-American detective Graham (Don Cheadle) is a lout to his Latin-American girlfriend/partner, Ria (Jennifer Esposito), one moment, a silently suffering son the next. Those demographic markers arenít mere diversity concessions: Crash depicts an L.A. where different cultures and ethnicities co-exist but havenít come to terms, where Persians donít understand why theyíre derided as ďArabsĒ and a daughter of Puerto Rican and El Salvadoran parents bristles at being called Mexican. Itís also an L.A. melting pot where a beat cop can be a hostile bigot during a traffic stop one moment and a life-saving hero the next. If Crash meanders through its elliptical episodes and feels both emotionally arresting and intellectually incomplete, itís only because by dramatizing this many voices with something to say eventually no one rises above the tumult.