Hello @Mr_Zuhair_16
You can get this trailer by editing your save.
If you know how to open game.sii file just watch the video.
1. You need to download Sii_decrypt.exe (to decrypt game.sii file) and Notepad++ if you don't have it.
2. Make sure, that your ingame profile is not saved in Steam Cloud.
3. Open config.cfg file that can be found in: This PC/Documents/Euro Truck Simulator 2
4. In config.cfg find uset g_save_format "0" and edit it into uset g_save_format "2".
5. Open the game and follow everything made in this video.
If you can't find your trailer in game.sii, then attach the trailer to your truck, save your game, find in game.sii file "assigned_trailer", copy the _nameless... value and insert it into the find window.
I hope this helped you.