Array
(
    [Order] => Array
        (
            [user_email] => st@kr.com
            [billing_first] => Steve
            ... //more excluded
            [total] => 5000
        )

    [Product] => Array
        (
            [0] => Array
                (
                    [id] => 1
                    [price] => 5000.00
                    [quantity] => 1
                )

        )

)

Notice (8): Undefined index: id [CORE/cake/libs/model/model.php, line 1391]

Model::__saveMulti() - CORE/cake/libs/model/model.php, line 1391
Model::save() - CORE/cake/libs/model/model.php, line 1355
Model::__save() - CORE/cake/libs/model/model.php, line 1778
Model::saveAll() - CORE/cake/libs/model/model.php, line 1673
CartsController::saveOrder() - APP/controllers/carts_controller.php, line 128
CartsController::checkout() - APP/controllers/carts_controller.php, line 172
Dispatcher::_invoke() - CORE/cake/dispatcher.php, line 204
Dispatcher::dispatch() - CORE/cake/dispatcher.php, line 171
[main] - APP/webroot/index.php, line 83

if ($this->Order->save($this->data)) {
    for($i=0; $i<sizeof($this->data['OrderProduct']); $i++){
        $this->data['OrderProduct'][$i]['order_id'] = $this->Order->id;
    }
    $this->Order->OrderProduct->saveAll($this->data['OrderProduct']);
}

$this->Order->create();
    $this->Order->unBindModel(array('hasAndBelongsToMany'=>array('Product')));
    $f  = $this->Order->save($this->data,false);

    /* Save extra columns in HABTM TABLE */
    $this->Order->bindModel(array('hasMany'=>array('OrderProduct')));
    $q = array();
    if (!isset($this->data['Product']))
    {
        $v  = false;
    }
    else
    {
        $v =true;

        for($i=0;$i<count($this->data['Product']);$i++)
        {
            $this->data['OrderProduct'][$i]['order_id']     = $this->Order->getLastInsertID();
            $this->data['OrderProduct'][$i]['product_id']   = $this->data['Product'][$i];
            $this->data['OrderProduct'][$i]['quantity']         = $this->data['quantity'][$i];
            $this->data['OrderProduct'][$i]['state_id']         = $this->data['State'][$i];
        }
    }

    $s  = $this->Order->OrderProduct->saveAll($this->data['OrderProduct']);

$this->Order->unbindModel(array('hasAndBelongsToMany' => array('Product')));

$this->Order->bindModel(array('hasMany' => array('OrdersPost')));

$this->data['Order']['id'] = '1';
$this->data['OrdersPost'][0]['product_id'] = '15';
$this->data['PostsTag'][0]['price'] = '5000.00';
$this->data['PostsTag'][0]['quantity'] = '1';
$this->data['OrdersPost'][1]['product_id'] = '16';
$this->data['PostsTag'][1]['price'] = '4000.00';
$this->data['PostsTag'][1]['quantity'] = '2';

$this->Order->saveAll($this->data);

CREATE TABLE orders_products (
  id integer,
  order_id integer,
  product_id integer,
  ...