Hello I am close to ordering a new car and the salesman was discussing Supagard products to protect the exterior and the interior of the car. I am interested in keeping the seats etc in tip top condition and have always used Mer to keep the exterior sparking. Has anyone had any experience of these treatments, either good or bad? Does it alter the colour of the fabric in any way? Is there any chance that it could go wrong on the outside and how do they keep it off the black plastics which are not glossy when they apply the exterior treatment? Thanks for your help, PeterT.