Well, I think I made some good progress today. The trunk side cleaned up pretty well. I used acetone with a microfiber cloth and lightly rubbed to remove all the spatter paint. The variation is shades shouldn't be noticeable after installed in the trunk. Where the trunk side stood up well to the acetone, the interior side is made of different material and does not play well with acetone. I still used it as dry methods didn't remove it at all. The acetone darkened the cardboard quite a bit - we'll see what it looks like after fully drying. To clean the main surface of the interior side, I put a latex glove on my hand and using my finger tips lightly rubbed the cardboard in small circular motions. That essentially removes the top layer of cardboard (and dirt) without disrupting the appearance (before is left of the center yellow ink line, after is to the right). I stayed away from the yellow ink since I didn't want to remove it. Still have all the repair work to do on the tears, but I think it will end up back in the car
