First of all, the trailers do not appear in the freight market any longer. But I don't think that is so important since you can just have it as an owned trailer instead and that is way better.
Secondly, when my trailers appear in the AI traffic the shadow looks absolutely trash: (this image shows the same problem on another mod I made 2 years ago)

I am pretty sure the problem comes from that I were using "KRONE Profiliner (Two-sided) by Matdom1988" as my trailer base. This is probably an old trailer model that does not look nice in newer versions of the game. And I need a 2-sided trailer model for skinning this appropriate trailer. I have tried using the Traffic trailer skin template in Mods Studio 2, and as far as I can see, it does not provide 2-sided functionality, it takes the same part of my image file and applies it for both sides of the trailer.
So my question comes down to exactly what I put in the subject: How can I make a 2-sided trailer skin for AI traffic in Mods Studio 2?