Cannot search for certain cars in the Auction House? (Ex. FE edition cars)

It seems I can’t search for a lot of cars in the auction house

For example If i go to Car Collection I can see a SuperSport FE (Chevrolet Super Sport Forza Edition)

but If I go to the Auction House and Filter Chevrolet for Make then ‘Model’ doesn’t list it at all

Why is this not possible?

Because If I just filter for Collection Tier: Legendary eventually the same car that is not listed for Chevrolet will randomly pop up between all the other Legendary Cars

Why was the Auction House downgraded from Forza Horizon 3 which released before?

Why can I still not filter for ‘Not-Owned’ cars in the Auction House?

Try selecting FE cars in the advance search options. X from the search menu.

maybe because that car isn’t available in the auction house because it has only been a gift car so far and gift cars cant be sold

I wonder when it will appear in the search at the auction house - I have / do not have this vehicle - so that you can only display vehicles that we do not have.

I use the filters. Prize cars aren’t in the list.