SL 350 BJ 2009 – Always mold in the trunk

Hello dear SL’er, I bought a SL 350 BJ 2009 from first hand 2 years ago and this is outside, both inside top in shot and has with 35,000 only very few kilometers. My problem is that I noticed last year that in the trunk under the plastic tub where the Tirefit is located, water had accumulated and everything was moist. I noticed after a heavy rain that there was always a little water left and right in the trunk. At first I always had it with a Han But when I had looked more closely, the lower tub was soaked and the water was already inside about 2 cm high. I then to my friendly MB dealer and they had the water drains (were completely clogged, strange, because the car was standing most of the time at the previous owner in the garage) cleaned and the seals were completely replaced. Then during this hot summer I had the car removed and as I said it was not much. and the trunk in hot weather often always left open so that it “dries out” properly. Then came the autumn and I noticed again after rain a few drops left and right and it slowly formed mold, which I of course always immediately wiped away. Where does this come from? I also always fit on the trunk lid open that nothing runs in. Do you have a good idea how to get the mold away? https://www.amazon.de/dp/B076VQXW51?… I think with this means of Am azon should I get the problem under control, what do you mean? Somehow I turn around. *Sigh* Daaanke in advance for your input