Installation

In Blender open Edit, Preferences, Get Extensions, then use Install from Disk and pick the trailer_caravan_generator zip.

Usage

1. Open the Trailer tab in the 3D viewport sidebar (N). With nothing selected, click the picture to pick one of the 21 trailers, then press New Trailer. You can also use Shift+A, Mesh, Trailer & Caravan.
2. The card at the top shows the trailer. Click its picture to switch to another preset. Surprise Me makes a random trailer, Variation changes the current one and New Seed reshuffles the small details.
3. The Look box sets the finish, the colors, the side graphics and the model name painted on the side. Open trailers show their deck and load here instead.
4. Doors Open, Drive and Steer are animatable sliders. Awning Out rolls out the awning and Lights On makes the tail, marker and interior lights glow.
5. The closed sections below hold the details: body and size, running gear, windows and doors, roof and exterior, interior, wear and export.
6. For game engines set Detail to Low and use Convert to Mesh; the meshes have UVs, the origin on the ground under the middle of the trailer and plain Principled BSDF materials.