Based on my own and other's research
SystemID NES
00A8 b u 0 RAM is Lag Frame
043C b u 0 RAM Frame Counter
0596 b u 0 RAM Player 1 Speed
059E b u 0 RAM Player 1 Angle
057A b u 0 RAM Player 1 Standing
0531 b u 0 RAM Player 1 Pos X1
052C b u 0 RAM Player 1 Pos X2
053B b u 0 RAM Player 1 Pos Y1
0536 b u 0 RAM Player 1 Pos Y2
055C b u 0 RAM Player 1 Lap Progress 1
0570 b u 0 RAM Player 1 Lap Progress 2
0561 b h 0 RAM Player 1 Current Lap
076D b u 0 RAM Player 1 Finish Position
05F2 b u 0 RAM Player 1 Money 1
05F6 b u 0 RAM Player 1 Money 2
0572 b u 0 RAM Player 1 Pos Z
058E b u 0 RAM Player 1 Floor Z
05B2 b u 0 RAM Player 1 Zipper Boost
06E8 b u 0 RAM Last Inputs
074B b u 0 RAM Boost Counter
06E2 b u 0 RAM Traffic Light Timer
0397 b u 0 RAM isRaceActive