I have an Eberspacher Handiwash unit, which i stripped out of my defender a few months ago for sale. Ideal for the dedicated deer stalker to have fitted to a vehicle in order to a have a proper hot hand wash and clean up after a gralloch.
Its the larger of the two models with hot(in-built heater) and cold taps, if you have not seem them before it has a large tank inside, a fold down bowl/sink which when you fold it back up empties the water into a sump tank built into the unit which you drain off when necessary using a long pipe which you stick outside of the vehicle.
It runs off 12volt.
See the spec here http://www.eberspacher.com/products/handwash.html
The company are based in Hants so I assume parts are still available. I have not used the unit so cannot guarantee its 100% working order but it was an ex utilities defender so i would assume so. They seem to be around £300-£350 new.
Collection only from near Midhurst.
Looking for £50, PM me for further info