In the early seasons Gary had a driving licence and was shown having hired a car to spy on Dorothy as seen in season 4, episode 2, "Infidelity", and in season 3, episode 2, "Bed" is seen borrowing Dorothy's car to go to the chemist to buy antacid; but by season 6 he can't drive and has never driven, as seen in season 6, episode 3, "Jealousy"