Basically half of the people are police and half are hoons. The hoons drive around a certain area e.g. Byron Bay and if the police catch them going above the speed limit (changes depending on what the leader decides), or dangerous driving (burnouts, driving on wrong side of the road, driving through a roundabout then they are pulled over by the police and can either run and if they are caught when they run they either change to a cop or have to hop in a slower car (once again depending on the rules.) Normally if the person just pulls over the rule is 3 times pulled over you become a cop. It all depends on the leader and what they decide but that is the general gist of things.