What's wrong with you. Never clean it, it has history in there. Empty it once a year and find all sorts of treasure, my last kitbag had a mouse setup house in there during the winter because I left it in my shed. It ate my Jt Skinzs for nesting in. If you get too much mud in the wheels that's the only excuse. If it's got to go in a clean car wrap it in a bin bag but never clean it. Crap is the only thing that holds it together.