Modder MrVicho13 has transferred the entirety of Mario Kart 8's N64 Yoshi Valley course into Grand Theft Auto 5.
The iconic cartoonish textures from Mario Kart 8 were ripped by a Mr. Ray Koopa before MrVicho13 converted and optimised them for the mod. More maps will be made available in future so perhaps your favourite will be introduced eventually.
Below you can see the mod in action and, if you're playing on PC, download if you yourself from GTA5 Mods.