There appears to be quite a discrepancy of data about the number of carwashes in the United States. Then there are different types of carwashes; Fixed and mobile. Amongst the fixed site carwashes there are coin-op self serve washes, Flex Service Robotic, Conveyor Conventional, Gas Station Rollover and the Touchless automatic.
You can pick up a carwash survey from any of the four major industry magazines or the co-marketed service industry magazines like; C-Store News, Oil and Lube News or any of the Auto Service Industry Association magazines and there are about seven of them. Some of the surveys in these magazines have broken down by region. Percentages of course are worthless unless broken down by area, even a manufacturer, better know that if it is going to set up a dealer network, sales teams or use existing channels of distribution. Those who study the industry need to be cognizant of the available data and its worthiness.