i was browsing the net and came across this interesting 12v shower unit, now it has a pump that can be put inside a water container, it can connect to our battery, you can run cold water as normal, or the flick of a switch you get hot water, great for winter time, we could change the hose to small bore, and take the shower head of, and fit directly to the spray nozzles, heres a pic of it, only £39.99