Certified pre-owned 2012 Prius II. Very pleasantly surprised so far. Now, what is this I hear about a secret storage place for the trunk cover thingy?
Look for the storage space just under the trunk floor, just above the tray on top of the spare tire. The cover should fit in there.
Welcome to PriusChat, which you'll find is an amazing source of all things Prius. The information you're looking for is on p. 335 of the destruction manual (at least it is for my 2009 Gen II "ChuggyPig") Good Luck, and Congratulations on getting a Prius!
As I recall, there is even a space for the wheel lock key, if so equipped, in the foam cutout for the lug wrench in the trunk.
Cool! I didn't know there was a place for that trunk shade cover thingy either. Here's a couple of pics where it goes.