Yeah sorry, it's the Festival of Speed you want. There are vintage cars through to historic racers (Le Mans, rallies) through to F1 cars competing in the hill climb up past Goodwood house.
On the Friday if you buy a grandstand ticket it's a roving ticket so you can sit in any of the grandstands up the hill. Well at least that's been the case for the last 4 or 5 years I've gone. Sunday is absolutely heaving with crowds though - Saturday less so but we have found Friday to be the best day for both crowds and traffic.
One other thing to watch out for is the amount of time you queue to get in. Get up as early as possible (gates normally open at 6am) to avoid queuing for 1 or 2 hours!
Some of my photos from previous years are on my site
here but apologies for the pics as they were mostly taken with P&S digicams.