Well I spent the better part of yesterday doing most of the exterior of my A4. Started claying at 11 and clayed till 2. I used mothers clay kit which was the clay bar and their showtime QD. I will say it is very esay to use, and the finish when your done is smooth with no bumps, very nice. I have alot of little lite scratches all over the car, like the owner took it through automatic carwashes, or just wasnt carefull. So after the clay, I washed with dawn again and dried. Now I would have really liked to polish out some of the scratches, but just had IHG and blitz. So i just put the IHG on and buffed off and this took care of most of them, but still are some there. After the IHG the paint looked good and pretty slick, but after a coat of blitz the paint looked wet and deep. Now I can still see tiny scratches/ swirls after that with a close look, but all in all I would say it looks good.