I don't use or need hot water, my tank is 500 L although I could have gone bigger if I wanted. Not sure what the hotwash looks like but if it is anything like an L5 , I'm sure I could have fitted one in ? I carry a supermax 40 in the back sideways . You need a taller hard top and a custom tank but it is certainly possible. I needed a work van and family car in one vehicle hence my decision but everybody's reasons will be different.