I've had some light scratches and dings in my cargo area and even on the tailgate surface of my Fortwo. Most of them were there when I purchased the car used. Usually when you get a scratch in the plastic it causes the edges of the scratch to be raised up higher than the surrounding plastic. I got me a piece of 150 grit sandpaper and lightly sanded by hand the scratches. Try to stay off the surrounding area as you will erase the vinyl grain that is cast into the plastic. After a light sanding and thorough cleaning of the area with a cleaner like Windex, I applied a liberal coat or two of furniture polish, preferably the kind with bee's wax in it. Then buff it off with a soft rag. It really makes the plastic glossy and it really helps hide damaged areas. Trying to even up badly damaged areas like you have can be leveled up with elmers glue but it is hard to level it out on side panels because gravity wants to pull it all down to a run and it is next to impossible to repair like that without it being noticable because the glue doesn;t match the textured grain of the surrounding plastic even though it dries clear. If the damage is extensive and you're really picky about your interior appearance I would consider replacing the side panels. You can find them used on LKQ. The plastic that is on the tailgate is the slipperiest plastic I have ever seen. You can barely sit on the tailgate without sliding off. DCO
My doors had some scratches on the inside when I bought my 2008. Those raised edges really bothered me, so I took a new paint scraper blade and carefully slid the blade along the raised part and shaved it right off. Then I used a dark grey Sharpie (perfect match) to color in the scratch. Looks and feels much better.
The plastic in the cargo area scratched real easy. They make it so soft.=, and yet the plastic on the tailgate interior os so slippery. They put cloth on the dash which is a good idea to keep it from fading and noticing imperfections, but they couldn't put a little carpet on the cargo hold sides?
When I ordered my panoramic roof from "part my ride" it came packed in a large box with an extra piece of carpet from the boot if some other type of small car. So I found that it fit closely enough in the cargo floor over the engine that I made it a permanenet part of the car, and the color matches perfectly. I little extra carpet over the engine helps because it does get warm, and I certainly don't want to melt those gallon buckets of ice cream I get at Walmart before I get it home. DCO