除非您以编程方式（即编写代码）来完成此操作，否则无法完成此操作。
当Magento添加一个产品时，它首先查看报价/购物车是否已经存在。如果存在，它会拉取该产品并添加到数量中。没有办法关闭此功能。
通过编程，您可以非常手动地向购物车中添加商品。

$cart = Mage::getSingleton("checkout/cart");

foreach ($products_to_add as $product_id => $custom_options) {
  $product = Mage::getModel("catalog/product")->load($product_id);
  $options = new Varien_Object(array("options" => $custom_options,
                                     "qty" => 1));

  // some products may result in multiple products getting added to cart
  // I beleive this pulls them all and sets the custom options accordingly
  $add_all = $product->getTypeInstance(true)
      ->prepareForCartAdvanced($options, $product, Mage_Catalog_Model_Product_Type_Abstract::PROCESS_MODE_FULL);

  foreach ($add_all as $add_me) {
    $item = Mage::getModel('sales/quote_item');
    $item->setStoreId(Mage::app()->getStore()->getId());
    $item->setOptions($add_me->getCustomOptions())
      ->setProduct($add_me);

    $item->setQty(1);
    $cart->getQuote()->addItem($item);
  }
}

// when done adding all the items, finally call save on the cart
$cart->save();