I see nothing wrong with driving a truck with no hood, fenders, doors, bed, or muffler. But I guess that is why I will never live in California, just too many rules.
One reason is the amount of vehicles and in my opinion the only place an open header sound good is on the drag strip. I do not want to hear it on the street and most of all on the trails where I am trying to gather my thoughts. It seems like on the trails the guys with the loudest exhaust have to blast them in the middle of the night in a drunken stupor thinking they are cool. Nothing Mr. Glock will not resolve.
I have had two windshields taken out from A-holes with lifted PowerJokes and no mudflaps. They are not that hard to make detachable for the trail. run them.