[Scenario]

Try this:

pawn Код:

new
    lastVehicle[MAX_PLAYERS]
;

hook OnPlayerExitVehicle(playerid, vehicleid)
{
    lastVehicle[playerid] = vehicleid;
    return 1;
}

CMD:detain(playerid, params[])
{
    if(IsACop(playerid))
        return 1;
    if(sscanf(params, "ud", iID, iSeat))
        return SendClientMessage(playerid, COLOR_WHITE, "SYNTAX: /detain [nick/id] [seat 1-3]");
    if(iID == INVALID_PLAYER_ID)
        return 1;
    if(iSeat < 1 || iSeat > 3)  
        return 1;
    
        TogglePlayerControllable(iID, false);
    PutPlayerInVehicle(iID, lastVehicle[playerid], iSeat);
    return 1;
}

CMD:eject(playerid, params[])
{
    if(GetPlayerState(playerid) != PLAYER_STATE_DRIVER)
        return 1;
    if(sscanf(params, "u", iID))
        return SendClientMessage(playerid, COLOR_WHITE, "SYNTAX: /eject [nick/id]");
    if(iID == INVALID_PLAYER_ID)
        return 1;   
    if(GetPlayerVehicleID(playerid) != GetPlayerVehicleID(iID))
        return 1;
        
        TogglePlayerControllable(iID, true);
    RemovePlayerFromVehicle(iID);
    return 1;
}

You'll need to change the "hook" line and just take the code from inside and put it into OnPlayerExitVehicle().

EDIT: I forgot one thing and changed the two commands, sorry.