In my previous workhorse ('88 Isuzu Trooper) I carry two different-sized ball hitches, a towchain, a towrope, a come-along, a full toolkit, jumper cables, whole bunch of bungies and rope and straps for securing stuff, first-aid-kit, spare anti-freeze (which I've only used for others), spare oil, spare water, spare brake fluid, spare steering fluid, spare fan belts, flashlights, folding chair, blanket, ... and that's just off the top of my head. That Trooper put on less than 500 miles last year, primarily towing trailers.
In my iMiEV, my solution was to put the flashlight in the glove compartment and stick some Rubbermaid containers in the back, but they're empty most of the time and perfect for carrying groceries. Plenty of room to stow your 'stuff' if you really feel you have
Truth be told, when I took one of my extended day trips in the iMiEV last week (>150 miles) I did take along a spare tire off my Insight and a jack and lugwrench in addition to a boxfull collection of 240vac adapters and extension cords and my SPX L1/L2 EVSE.
Think about it - the iMiEV is primarily used for local driving and all that other 'stuff' is simply not needed. I keep my glasses in the small tray forward of the shift lever, and I agree Mitsubishi could have used some creativity in creating small cubbyholes but a trip to your local dollar/auto store should fill your doodad storage needs.