A friend of mine took a similar vehicle out onto the dunes and struggled. We suggested running 10psi and 4WD Low - he didn't have any problems after that. He started out in 2nd gear instead of 1st though.
"Opportunity knocks once" Not true... In some cases it never comes knocking, you have to go out and grab it by the hippie pony tail, and drag it over to your place for wine and chocolate."