[Pedraum]

Aqui funcionou perfeitamente amigao...

pawn Код:

public OnPlayerCommandText(playerid, cmdtext[])
{
    if (strcmp("/parar", cmdtext, true, 10) == 0)
    {
        SetVehicleVelocity(GetPlayerVehicleID(playerid), 0.0, 0.0, 0.0);
        return 1;
    }
    return 0;
}