ambar, pdk, lepascals Mario Kart 64 Texture Pack
ambar, pdk, and lepascals Mario Kart 64 texture pack covers a few of the levels with realistic textures. Self admittedly the artists claim to of just grabbed images off of google and put them over the top of the original textures.
The choice just to use images straight off of google can make certain parts of the game just look hugely out of place.