going back tot he original question
I used black silicone to fill up the holes. Silicone by itself tends to dry and smooth itself into a shiny surface, looking nice in your bathroom, but nnot here. If you wait a while for it to set, you can model its surface kind-of-like clay, and push some texture in. So I used some sandpaper to dull it, and landscaped my favorite grain (pattern) into it with a non stick plastic (like a PP straw, steel works as well). If it sticks, dip it in dishwasher soap first before shaping the grain.
Not as good as original but for 5 euro's and 1 hour its quite rewarding.
practice perhaps outside the car first to learn about the drying time and stickiness of your silicone. you don't want it to stick to all your fingers while you're still in the car.