Here's the real thing at Daytona:
But, here's where the "Hey, that's a cool idea!" starts:
Here we see the grandstands with a piece of asphalt and 1/64th race cars for scale. Looks like a crowd full of people just like you see on TV? The answer to your question is 'Q-tips'. I cut off each end, about 1.25" in length. These 'ends' become 'people', after they've been dipped in various food coloring. Paint would work equally well.
Here's another shot of the grandstands.
Here's the main grandstand with the media booths and/or luxury boxes. I still need to paint the glass a dark blue or black, then cover with PVA glue to simulate the shiny glass.
"Ah, that's how you do it!" (side view with 1/64th cars for scale) The stands are made from 3/4" styrofoam, with steps cut into the foam with a hotwire and painted grey. Then the 'people' are dabbed in pva glue and 'stuck' into their seats. From 4 feet away it looks like a rowdy crowd.
Here's a 'tall' grandstand, with right and left cutouts for fan access to the services below.
Here's a 'tall' grandstand next to a cutout to see how they look together.
Here's a 'tall' grandstand next to one of the 'short' grandstands.
Other than making section tracks, I also need to create inner and outer 'crash' wall sections to frame in the track.