water/air isn't that big of a deal on the street. Ask any Sy/Ty, Cobra, or Lightning owner. You don't have to swap water out unless you want to. You can either use a small radiator to cool the water, or circulate it through a cooling tank. But here's the real kicker. If you're going on a long trip, it probably won't be at WOT with full boost so get this, the water doesn't HAVE to be iced down! :o Scientists have been researching this for years and finally got it squared away so you can drive with ease.

BTW, you can also have a hobbs switch turn the pump on at say 2psi, that way water is flowing by the time its needed. Not rocket science at all.