I have a passenger every time and I have had a few times where I needed to have packages removed due to them being to big for my car or having to many they don’t fit or affect my visibility. However I don’t see my passenger as being the reason I’m having to return the packages. I put all envelopes in the front so they are stacked up on the passenger floor leaving no leg room but that takes the room that I would of used had I placed them on the seat where they are. All the boxes go in back and trunk. If the big boxes don’t fit they go back. I wouldn’t have put a big package in my front seat regardless though, passenger or not because it affects my visibility. I’m not sure having a passenger makes that big of a difference, they can hold things in their lap put stuff on the floor and it makes up for the room you would of had on the seat if they weren’t there. They are probably just returning them because they legit don’t fit or they are returning them because they simply don’t want to deliver them