Barricade Bus.
You can find a free PDF tutorial on how I approach using UV Masks to blend in dirt and grime over the base textures in UE4, along with a similar version of this Mesh and Textures in my ArtStation Store or on Gumroad -
https://www.artstation.com/marketplace/p/p3Mn/uv-masks-tutorial-barricade-bus-asset
https://gumroad.com/hamishames
Thanks for checking it out, and I hope that it can be of use to you.