FAYETTEVILLE, N.C. — Ever since 81-year-old Mae Hodges bought a used Volvo, “strange-looking people” have been approaching her around town to pay compliments. “They tell me, ‘Thank you for being a pioneer in our movement,’” Hodges says. “I have no idea what they mean.” The flow of appreciation began after she started driving the nondescript Volvo wagon, which bears several bumper stickers. One sticker shows a multi-colored flag, another a pink equal sign, both of which Hodges found “very cheery.” “I left them on the car because the bright colors remind me of my flower garden,” she says. “Bill used...