Hi Phil, I absolutely agree with you - even if a vehicle is spotless on the outside, when the wheel liners are not clean and deep black colour, it diminishes the looks of the car. At first one may think that this is a negligible, small detail, but it makes a huge difference - just like you said. Please see my video called "Cleaning, conditioning, restoring, beautifying plastic parts" - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-CqvLBced4qY.html and Starting at 4:22 in "Rear Suspension Bump Stops - Remove, Restore, Reinstall + Prevent Corrosion/Rust": ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-CqvLBced4qY.html The products I used for the front wheel liner are the exact same products which I used for the rear bump stops as well (video above).