I haven't managed to look at the game scripts yet to find what native they're using; I have a feeling it might just be 0xC970D0E0FC31D768 and 0x6DEE944E1EE90CFB but I could be wrong. 0xC970D0E0FC31D768 SET_TYRE_TRACTION_LOSS_MULTIPLIER
0x6DEE944E1EE90CFB > SET_VEHICLE_REDUCE_TRACTION