Plot:French Postcards rings both comic and true. The believable, fresh-faced characters are young naives from American colleges spending their French-English dictionaries, they compulsively seek out hundreds of monuments, romanticize the nomadic artist's life, and look for grown-up love. The French tutor them well, as befits their reputation. Jean Rochefort is the harassed headmaster with a hankering for affairs, and Marie-France Pisier is his very sexy wife. Watch for a newcomer named Debra Winger, and another-Mandy Patinkin.