[Ballu Miaa]

You can only attach one object per vehicle. Even though in your code you were using the same variable name for the two integer values. Which is not allowed. Thats why you were getting that error.
The correct code can be:

pawn Код:

CMD:cl(playerid,params[])
{
    // infernus:
    new myobject = CreateObject(18641,0,0,-1000,0,0,0,100);
    AttachObjectToVehicle(myobject, GetPlayerVehicleID(playerid), 1.434999,0.000000,0.000000,181.799896,391.500518,178.200042);
    return 1;
}