I dont believe I saw on the rules that there is a certain side to overtake on. As in real trackdays the side to pass on is decided by whether the track is clockwise or anti-clockwise (clockwise = pass on the left, anti-clockwise = pass on the right). Just to add to the reality and would make it easier for both the drivers to pass cleanly if they know which side the car is going to pass or pull over.
Jamie
Jamie