(Wall Street Journal) — Car companies have long tapped high-profile celebrities to spread word of mouth about new cars by test driving them around town. Now they are turning to a similarly powerful but cheaper source: young social-media influencers who have strong online followings. For its new compact Lexus, Toyota Motor Corp. is enlisting people with a strong following on Twitter and other social media to create buzz around its products. Its new campaign includes online videos that show actress and comedian Whitney Cummings interviewing an array of social-media heavyweights as they take the Lexus CT 200h for a spin around their hometowns. The stars of the campaign include Baratunde Thurston, Web editor of satire website the Onion; Brian Solis, a marketing guru and social-media expert; and Richard Quitevis, or DJ Qbert, a well-known disc jockey.