I generally clean the engine compartment about twice a year using the same bucket of warm soapy water that I use to wash the VX. I use a tire brush to get into nooks and crannys. Just a light cleaning and then a hose down with the nozzle set on "shower". I do the engine compartment first, then take her for a short drive when I'm done detailing the exterior, to dry it out. I've never had any problem with water in the electronics.