I've been importing assetto corsa maps into BeamNG world editor objects for a while now, but I've never run into this issue. When I carry out my regular process of using blender to export the map models into a DAE file with the correct scene format, the geometry of the object when imported into BeamNG is all messed up. It only seems to be happening around the trees, so that may be a hint, but I'm really not sure. I've tried this with several other objects too in other "levels" folders. But they all exhibit similar issues. I've tried fiddling around with the DAE export settings but they all seem to lead me nowhere. I am hoping that someone more knowledgeable can help me out troubleshooting this weird issue!
Oh that's just inverted normals or whatever, just set the texture to double sided+invert blackface normals