My advice would be to arrive as early as possible, car parks open at 06.30 gates open at 07.00. A good place for seeing the cars on the hill climb is at the top, on the loop where they wait before returning back to the paddocks. Whilst you are at that end, the forest rally stage is well worth a look there are many places where you are very close to the action. The paddocks are always interesting but they can get very busy. The display at the front of Goodwood house is always impressive, this year is a tribute to Porsche. Close to the house is the 'Cartier Style Et Luxe' a concours display which often has some interesting cars. Hope you enjoy your day.
Graham