Hi,
There is no hikashop_products_container class in HikaShop, so I'm still not sure where you're trying to add your id.
I'll suppose that your talking about the div hikashop_container of your products listings.
But for that, the classes and ids already available should be enough ?
For example:
.hikashop_category_listing_13 .hikashop_product_column_3.hikashop_product_row_1 .hikashop_subcontainer{
background-color: red !important;
}
will turn the background red for the product 'Normandy, Banana Pudding & Vanilla Wafer' on your listing.
}