On purpose built circuits, mostly at existing race circuits such as Croft and Lydden Hill, up to 12 saloon cars compete in races up to 5 laps on mixed tarmac and rough surfaces against each other and the clock. The cars range from Minis to 600+bhp escorts and similar. With races approximately every 7 minutes, and a full programme of about 45 races in the day, marshalling is never a leisurely hobby.