I’ve been eyeballing this cage thing on amazon I could mount to the roof rack. Would be ideal when transporting gasoline cans and other things I don’t want stinking up my car. Being a hatchback with fold down seats I got plenty of room but the last time I spilled a few drops of gas inside it took a week to air out the fumes.
If you have a tow hitch, you can also consider a cargo rack at the back.
This is what I got:
https://imgur.com/a/unnkOvOI also got a roofbar and box, but i pretty much only use those for skies.