When ordering a model not publicly displayed (even the ones available for sale), the shopping cart does not display its picture anymore, but instead the text "this model is no longer publicly available".
It's worse than just the image being missing in the cart. If you click on the item link from within the cart you end up at a page not found error rather than the item page.
I noticed this when using the product varient option as the variants are available for sale but not publicly displayed. The image is shown in the popup when the variant is added to the cart, but when viewing the cart the image has gone, and as I said the link leads to a page not found error. You can try it yourself through this item -- just try adding the one or two brake variants to your cart.