Trolley through the River Arts Fest

I'm glad that the Trolley will keep operating during, and right through the middle of, the Fest.

Next year they could put art on the Trolley. Maybe they're doing it this year.

What kind of art could you put on the trolleys? What immediately comes to mind is print advertising, but I don't remember if trolleys have advertising frames, like buses. Also, they could show family-safe digital art in trolley-modded flat panels.