Mario Kart 8 - Default Kart

To install this mod:

Using OpenIV go to x64w.rpf\dlcpacks\mpindependence\dlc.rpf\x64\levels\gta5\props\dlc_lev_des.rpf\ and replace ind_prop_dlc_roller_car.ydr in that archive.

Then when you go ingame you can easily access the kart by pressing F8 to bring up the Menyoo menu.

Go to "Vehicle options" → "Vehicle Spawner" → "Funny Vehicles (Old)" → "Roller Car"

then you’ll be put into the kart.