I like stacks on a truck but imo to me there needs to be some requirements for them. first off if your engine is so power dead it gets passed by priuses, it shouldn`t have stacks. Also I think it needs to be diesel and smoke. Also they have to be 5in. or bigger. It amazes me how many times I have seen people with 2 2and a half in. pipes sticking up through their bed and it just looks like crap.