There is simply no place to put anything without it rattling around, which is extremely annoying. I love the minimalistic aesthetic, but I do need to store an umbrella and a few other things. And I don't carry a bunch of junk in my car. But we need something. The CCI helps, but doesn't go far enough.
I currently use a floor standing trash container in the back that fits under the vents for the back seat. i found it on Amazon and it works well. I reach around and place the trash in with one hand, even as I drive. http://www.amazon.com/Talus-TrashStand-Floor-Litterbag-XL-Black/dp/B000ETQMIQ/