A Volkswagen logo is pictured at Volkswagen's headquarters in Wolfsburg, Germany, April 22, 2016. REUTERS/Hannibal Hanschke/File Photo FRANKFURT (Reuters) - U.S. authorities have found three unapproved software programs in 3.0 liter diesel engines made by Volkswagen's VOWG_p.DE Audi NSUG.DE unit, German weekly Bild am Sonntag reported, without saying where it had obtained the information. The soft