The kart meshes are stored in the .3df files.
FlintCar1.jpg


Brief format of the .3df files
0x130 4Byte#ofMeshes
0x134 4ByteOffsetToFirstMeshData
MeshData is 0x170 Bytes in Length including
4ByteVertexnumber and 4ByteFaceNumber
,,,,,
Offset To vertexes
Offset To faceindex

Vertexsection format
{Vertexes(X,Y,Z),Normals(X,Y,Z),UVs(U,V)}