Interceptor- you are right about Detroit of Belle Isle. I had to laugh when you brought up Offshore racing on that track as I remember press day before one of the OS events and Gene Whip flipped a little V bottom right dead center in front of the downtown lunch crowd.
Actually, I think Milwaukee has a good course. It's a little tight on the one end but the fans sure get a kick out of watching everyone come through there. Both courses prove (as do some others) that you can have spectators involved. However, outside of the old Miami Marine Stadium, it's almost impossible at most sites to charge admission so the events become dependent on sponsors. That again brings up the catch 22 of the sponsors wanting to expose their products to the maximum amount of fans, etc.