Check out Bus Setra topclass S 431 DT Low-poly 3D model on CGTrader for $20. High-quality Polygon mesh mesh by AzkA3D: 510846 polys, 283209 vertices.
STL (Stereolithography, filesize: 24.4 MB), OBJ (OBJ, filesize: 30.2 MB), DAE (Collada, filesize: 47 MB), BLEND (Blender, filesize: 31.8 MB), FBX (Autodesk FBX, filesize: 11.7 MB)