I bought a 1st aid road assistance kit from Costco; flash light, triangle, jumper cables, air compressor, blanket, 1st aid kit, and bunch of other stuff I never hope to use. About half of it fit in there, the other half is under the driver's seat. Also put in a foldable cloth "cooler", cause you never know when you might need to keep that six-pack cold.
What bugs me is that the cover for that compartment is sort of loose, it closes fine, the twist latches turn fine, but then the whole thing (especially the front part) dips down a little. Maybe something was there before my times and pushed it out so now it doesn't stay closed perfectly...