I made a skin for the dry van trailer, did the image, jbeam, materials. It's not showing in the vehicle selector or config. I'm confused on what to do with the files.
I would set up folders like this. yourmodname.zip\vehicles\dryvan\(place those three files here). Make sure that in your materials.cs file the file path matches the one that you make COMPLETELY, or else it won't work. Furthermore, if you place them in an unpacked folder in the mods folder (documents/mods/unpacked/yourmodname\vehicles\dryvan\threefiles) just like that, you can edit the skin in real time without unzipping the folder everytime to make changes. If that wasn't what you were confused about or you need more help, let me know. Also, if it is a skin, it won't show up in the vehicle selector, because it isn't a configuration
Do you have the files you created for your Dryvan? You could upload them here in a .zip for us to take a peek in and see if we can find where your issue lies.