The Dream Cruise is quite a spectacle if you can get past the large population growth in the area for that weekend. The estimated 2004 attendance was 1.7 million....

I planned to go this past weekend, but some things got in the way. It was a bummer though, I liver fairly close (< 1/2 hour) and up to and during the DC weekend, you see all kinds of classic and new muscle cars, sports cars and trucks out cruising around. I've gone for the past 3 years not including this one and it is quite the show. I would suggest that you try to go at least once.