Come spring I really want to detail my truck. With that I want to clay but have three questions on clay. 1- I see there are different grades of clay, I have never clause this truck the 3 years I have owned it. What grade would I get? 2- I see there is clay and also clay mitts, recommend either or for first timer? 3- I have pin stripe on my truck, nonpainted kind, do I not go over that with clay?