Scottish Lad

these trailer's are custom made, by save editing, you might find one if you search for Truckers MP mods, these can be used / made  on single player then once you have selected your trailer the way you want it, load into Truckers MP and you can use it, most people however have learned to save edit their Trucks and trailer's so you should YouTube how to save edit ETS2 and watch some tutorials, as once you get used to it it is very easy, just make a copy of your full profile, that way if anything goes wrong you can just delete it and put the copy back in so you don't lose anything. Their is also tutorials on the Truckers MP forum which you may find helpful here is a link to a good one.  Good luck and have fun.