Good Tip! I do this to every one of my models, but I use those fiber finger nail files. The drill and sandpaper probably gives better and more consistant results. . .
Go to Google, click on the "images" word and type in "1931 Mercedes SSKL." I couldn't find any pics of the real car, but there are some pics of a #87 model. All show it as having dark maroon fenders, wheels and dash, and a black #87 painted on the cowl sides.