I don't have a 4x4 at the moment but working on rectifying the problem. I am however a part of a few communities where the off road car is used a lot. Including the Search and rescue, those cars do get dirty but are always cleaned as soon as we get back. I also go off roading with my friends. They are not as quick to clean the cars after a trip, they usually get a proper cleaning 4-5 times a year.
I guess we'll see what kind I am as soon as I manage to get rid of the Getz and get a proper Icelandic truck