Missing Cars From Car Pass and Ultimate Add-ons bundle?

[Seacaller]

I'm going to list all the cars that are not appearing in my steam dlc manager, which I'm supposed to own because according to the devs, these cars are included in either the Car Pass or Ultimate Add-ons bundle:

Forza Horizon 4: Any Terrain Car Pack
- 1985 Porsche #185 959 Prodrive Rally Raid
- 1991 GYMKHANA 10 Ford Escort Cosworth Group A
- Can-Am Maverick X RS Turbo R

Forza Horizon 4: High Performance Car Pack
-2014 McLaren 650S Spider

Forza Horizon 4: British Sports Car Car Pack
-2004 Vauxhall VX220 Turbo

[maileater]

I own the Ultimate Edition which i bought in a sale in september 2021.
So far for now i've checked only the first car on your list (1985 Porsche 959):

In the list of owned DLC it is described as "1985 Porsche #186 959 Rally Paris-Dakar".
Within the game it is labelled like in your post "1985 Porsche #185 959 Prodrive Rally Raid".

And i bought it for zero credits from the dealership within the house menu.

[totophi]

I'm not sure I ever used the Steam DLC manager, and certainly not on this game, but I also got the Ultimate Bundle and confirm having access to these cars from within the AutoShow catalog in-game.