“SEX AND THE CITY” GETS ’EM HOT! Reps for the world’s highest-end luxury products are sweating, salivating and flinging money with both hands, begging producers for full-frontal exposure in the movie version of TV’s sizzly “Sex” saga for their boffo brands – Mercedes, Tiffany, Jimmy Choo, Manolo Blahnik, Valentino, Dior, Oscar de la Renta, Chanel, etc. The price tag? Even for a quick-as-this onscreen blink – sexy shoes worn by SARAH JESSICA PARKER; diamond bling dripping off KIM CATTRALL; CYNTHIA NIXON swilling buck-a-drop champagne; KRISTIN DAVIS dabbing her decolletage with pricey perfume; or CHRIS NOTH in a Mr. Big-style luxury whip – can cost anywhere from half-a-million Big One$$ to mid-seven figure$$! So far, Mercedes, Tiffany, Fred Leighton and Jimmy Choo have scored spots – and producers are giggling that “Sex” could be the first-ever flick fully financed by product placement gold.