Yes, BeamNG 0.4.0.6 will run on a potato. It uses an older version of the Torque Engine, has no dynamic ambient occlusion, lower resolution textures, and fewer physics calculation steps. However, you face a trade-off:
BeamNG.drive version 0.4.0.6, originally released on June 26, 2015, is significant as the final official release to support Windows XP beamng 0406 download free