An old professor of mine took his free-improvisatory combo and played for rush-hour traffic on a freeway once - he said they appreciated it. Maybe it's just a question of finding the right situation: a bully pulpit, or a captive audience.
I must admit that I'm guilty of the former; when I play church services as a guest artist (meaning that I'm basically unregulated), I tend to stick in a few pieces of contemporary art music. Most recently, it was Schoenberg's Kleine Klavierstücke (not truly contemporary, I know), but I've also done some Cage, Crumb, Webern, Rouse, Rakowski, and the like. I think not being able to escape makes people like things a little bit more, because the choice is "listen or don't listen," instead of "listen or do something while not listening."
Maybe a drive-thru would be a good place to set up an ensemble.