Lot of good advice above, to which I would add, get there early. Unsurprisingly given the location of Goodwood house, the Sussex lanes (and the A27) start to struggle with the weight of traffic from about 8am onwards Fri, and particularly Saturday and Sunday. Also, getting through the gates as they open at 7am, gets you into the paddocks when they are quiet and there is much fettling going on in advance of the days action. If you haven't been to Goodwood before, you will be astonished how close you can get to the cars being prepared...and how much damage you can do to your hearing!
Sunday is different from the previous two days as they have over the last 2 years introduces the timed 'shoot-out' for the 20 cars recording the quickest times over the previous 2 days. This is a good thing as you see some cars moving seriously quickly up the hill, but as Sky are involved, broadcasting live, the schedule tends to get a little stilted to accommodate TV ad breaks etc.
2001 3.2 Circuit Blue Coupe with pop-ups!
"If you want to argue that The Best Car in the World is a supercar, go ahead. But there is only one that makes the grade. Only one that's built properly.
Gordon Murray knows.
Rowan Atkinson knows.
It's the Honda NSX."
(J. Clarkson)