The price varies from a low of $14 to a high of $28, just depends on where you are and whether you get the RainX. I like the fact that usually it doesn't take them much longer to wash the van than it does for me to pay for it.
I go to Blue Beacon a lot, they're more ubiquitous, but prefer Eagle Truck Wash, as they use long handled brushes to clean the van. Iowa 80 truck washes usually do the same. I also like the truck wash across the street from the J in Knoxville, and the one just down the road from the J in Davenport.
And, of course, there's Turtles Truck Wash in Oak Grove, KY next to the Pilot.
But I've never actually been there.