Never mind cupholders. In an article called "Vehicle Features That Keep You Organized," Edmunds writer Holly Reich takes a comprehensive look at the techniques designers use to add utility to automotive interiors:
(Lincoln MKX) While center consoles holding iPods is no big whoop...
...some can be deep enough to hold laptops (Acura MDX).
Driver and passenger can have separate storage consoles (Audi Q7).
The Nissan Quest takes a cue from airplanes with overhead storage bins.
The floorboards on this Chrysler minivan fold up,
so the seats can fold completely flat into the floor.
Land Rover's assymetrical tailgate can be left
closed, but still provide access to smaller items.
The Dodge Nitro features a sliding floor to ease loading/unloading.
The Honda Element's rear seats fold up and out
of the way, providing a large, flat surface for
cargo. They're also waterproof, so hosing out
the urethane-floored interior is no problem.
Also be sure to check out Reich's piece "Is Your Car a Mess? Organize Your Car in Five Steps."