I would use it with high pressure as everything is already set up.
The reason I ask is I had this Rain-X container sitting around from when I tried it in the auto and was then unhappy with the result. I believe it has something to do with how my machine applies it rather with the product itself. Anyway, I thought I give it a try in the SS bay instead of the HP clearcoat protectant and see what my customers say.
Assuming that it goes on just like most other pump stations, I'd start using it at about a green, and plan to move downward until you get the effect on the car you're looking for. I'm currently using warsaw's version, weathershield, at one wash as a high pressure CCP. I think I have a blue tip in the hydro tank. But by the time it is drawn into the water stream the true dilution rate is much higher than the blue tip would lead you to believe. A 5 gallon container last me several months.
I have tried the rain-x years ago in a high pressure automatic that used a high pressure wax. I had a similar experience and it was too expensive. A frustration of mine is that there is a time lag before the CCP gets on the car's surface because the product has to travel through the HP lines just like a SS bay. By the time the product is coming out of the nozzles the gantry is half way through the pass. As a result all my washes using high pressure CCP have passes in a row. I now apply the premium products via low pressure.
BTW, there is a way to modify a lot of automatics to convert to a low pressure CCP application through the use of a relay. I installed a rain arch and
flojet to pressurize the CCP. I then tapped into the output that controls the CCP solenoid with a dual pole dual throw relay. I "break" the motor starter contact and "make" the air contact supplying the
flojet. Works fine. You could also use a foaming applicator.
