some basic addresses for player speed, position, turbo level, rockets, and mines.
CasualPokePlayer helped find some Random addresses at 6144 and 6350 for out of race and in-race random values respectively.
SystemID GBA
0D94 d u 0 IWRAM Player Acceleration
0D90 d u 0 IWRAM Player Rotation Delta
0E4C d u 0 IWRAM Player X Coordinate 1
0E50 d u 0 IWRAM Player Y Coordinate 1
0E5C d u 0 IWRAM Player X Coordinate 2
0E60 d u 0 IWRAM Player Y Coordinate 2
0E66 w u 0 IWRAM Turbo Fuel Level
0E70 b u 0 IWRAM Player Mine Count
0E71 b u 0 IWRAM Player Rocket Count
6114 d u 0 IWRAM Player Y Coordinate Previous Frame
61C0 w u 0 IWRAM Player X Coordinate 3
62A4 w u 0 IWRAM Player X Coordinate Previous Frame
6370 w u 0 IWRAM Player X Coordinate 4
6374 d u 0 IWRAM Player Y Coordinate 3
6308 w u 0 IWRAM Player X Coordinate 5
63EC d u 0 IWRAM Player Y Coordinate 4