He said the man's cards were used at the Huntly Mobil not long after the attack and they were now seeking CCTV footage.
A police spokesperson confirmed they were called about 5am to Great South Road, Huntly, following a report of a man being assaulted and having his vehicle stolen.
"The vehicle, a dark-coloured Nissan Terrano station wagon, has since been located and inquiries to establish its movements are ongoing.
"Anyone who witnessed this incident or who has information that might help police is urged to call 105 and quote event number P045119643."