[3ventic]

pawn Код:

new Float:x, Float:y, Float:z, Float:a;
GetPlayerPos(playerid, x, y, z);
GetPlayerFacingAngle(playerid, a);
SetPlayerPos(playerid, x-(DISTANCE_TO_MOVE*floatsin(a, degrees)), y+(DISTANCE_TO_MOVE*floatcos(a, degrees)), z);

Tested it and it works, replace DISTANCE_TO_MOVE with the distance you want to move the player.