I did nothing to personaloize my Civic, which I had for 10 years and sold to get the Element. (I admit I cried when the new owners drove off with it).
But the Tonka Truck is just so cute that it demands my attentions. So, after scouring this site for literally hours, here are the DIY modifications I've made:
Bright Blue bungee cords from WestMarine. They have all sorts of cool end peices that are either plastic or metal. Used plastic for behind the seats (so they won't scratch) and metal for the hooks on the floor. Cut to custom lengths for my own purposes. Put the manual and maps behind the driver's seat. ($20 for 25' of 3/16 in, 10' of 1/4 in, and a bunch of clips).
Cut out non-skid plastic shelf liner for the little compartments on the dash, the cubby up above, cupholders in between the two front seats and matching disks for the back seat cup holders. Got it at Target--nice, clear, ribbed vinyl. Didn't like the spongy, grid kind, looked a bit like some alien residue to me. Took forever to cut out the template then the vinyl and to trim, trim, trim to fit. But looks great and the cell phone no longer slides back and forth with each turn. ($2.50/Target).
Case-logic carrying case that folds flat and pops up to hold three filled grocercy bags. Also zips shut on the top to hide contents and has a net comparment that lines the front. ($19.99/Target). Put some grommets in the corners at the base in the back, added split rings and the 1/4" bungee (from above) slides through the rings and is firmly attached to the side latch hooks. No sliding or spilling of contents.
Got a cute litter bag with hawaiian looking floral design in blue and white. Has a roundish top, and velcro release at the bottom. ($4.99/Target) Tried hanging it from the shifter, but looked cluttered, covered up the subwoofer and the indicators along the left side. Fretted for a bit, then attached it to the bungee behind the back seat. Not too easy to reach from driver's side, but I just pass the trash to the passenger and have them drop it in!
Carabiners: 2 big blue ones to act as clothes hooks in back, 6 little black ones to attach to the latches as needed ($1.99 to 3.99 at REI).
Little Tiny convex mirrors for side mirrors ($1.39/each/Pep Boys).
Box of swiffers for the dust on dash ($2.49).
O rdered car mats and keyless entry (from H and A). Should arrive in next couple days. Will follow Element-J's instructions. He's the best!
Last, but not least, didn't go the hoola route. Instead got a clear, bluish glass, dragonfly to majestically sit atop the console. Slightly bobs and is held in place with a suction cup. No price, a gift from mom.