A “poor man’s” car once found on every street in America was among good company Saturday at the inaugural Atlanta Concours d’Elegance at Chateau Elan in Braselton. Thousands of car enthusiasts filed through the winery grounds to view and test-drive more than 170 rare and antique cars. At the center of this whirl of festivities sat a small group of vehicles: rare antique Chevrolets rippling with chrome, looking as if they just rolled off an assembly line.