The U.S. Postal Service is unveiling a new series of stamps Friday that feature five special cars. For the lowrider community, it's validation of a vibrant, artistic expression that blossomed decades ago in Mexican American and Chicano communities with the transformation of everyday cars into rolling masterpieces. The dazzling paint, glistening chrome, luxurious interiors and gravity-defying hydraulic systems are synonymous with lowriders and have become a part of mainstream car culture as symbols of creativity, pride and identity. The lowrider style now spans the globe, influencing popular culture as far away as Germany and Japan.