Filtering on “Not Owned” should obviously not show traffic cars and other unobtainable vehicles.
Yeah this was silly in 5. There were workarounds for some of them, but being told that the flat bed truck did not count in the story, which was they only place it ever showed up, was stupid.
Bring promo from the start and fix such issues. The odd traffic-only car is all good as it means you actually pay attention to what is out there, like the VW Rabbit in FH2, but at least make them all possible to get!