Are you driving a newer Prius? Do you carry a purse, wallet, wear sunglasses, need a place for your cell phone...? Then I must ask: where on earth do you put your purse or pack when someone is sitting in the passenger seat?! On the dirty floor where your passenger can step all over it? "Excuse me, can you please hand me my purse?" every time you need to root around in it?
This was my problem, until I found this cool cargo holder. It slips into place on the hump, and is held firmly in place by two strips of Velcro on the bottom (you don't need to attach anything - the Velcro on the tray grips your carpet firmly without any damage). The curved-up edges hold your purse, sunglasses, wallet, whatever! - it never slips off - and it's at nice height.
The Prius front cargo tray comes in two different thicknesses - you can select either the standard black textured plastic tray, or for $1.00 more you can select the "Deluxe" version, which is made of a thicker black textured plastic. Both are very sturdy!