I think hiding the vehicles you don't have the whitelist to should be a sorting option, or just having them hidden from the list until you purchase the whitelist from the owner.
It gets confusing when you're hiring a new player and they have 0 clue about what they are doing and don't know how to search for the vehicle you are asking them to buy, so just hiding all the vehicles you can't even buy would for sure fix the confusion with new players, gets rid of the clutter and overall is a QOL change.