By Lisa Schwarzbaum
Updated April 02, 1999 at 05:00 AM EST

A truck pulls up to a trailer-park home and runs over a plastic deer, crushing it flat. That’s the opening shot of Sparkler, and it’s the prevailing attitude, too, of this condescending comedy that regularly belittles every character in the guise of celebrating whimsy and regional exoticism. And no one is less generously treated than heroine Melba May (Park Overall) — the effervescent personality of the title — who’s got a lying, cheating, plastic-deer-crushing husband (Don Harvey) and a tinselly dream of making a new life for herself in Las Vegas.

Darren Stein, who also wrote and directed the vulgar, unfunny Jawbreaker, seems particularly amused by (or is that scared of?) the sexual potency of ”trashy” women; Melba’s old high school friend, for instance, is a pathetically sex-starved, over-the-hill stripper (Veronica Cartwright). But the guys don’t come off much better: The two good-hearted broads educate a trio of callow young men (including Freddie Prinze Jr.) who, judging from the dialogue, have never engaged in conversational intercourse with a member of the opposite sex, let alone touched one in any of her sparkly places. D