We also have a few new battle courses, since the battle mode now features proper arenas in this game. (gamingreinvented.com)
In Mario Kart 8 and Mario Kart 8 Deluxe, some Toad Houses can be seen in the backgrounds of the new Mario Circuit and SNES Donut Plains 3, as well as SNES Battle Course 1 in the Deluxe version, and on the ground below the SNES and N64 Rainbow Roads. (mariowiki.com)
also returns as a retro battle course in Mario Kart 8 Deluxe. (mariowiki.com)