GearXS via eBay offers the 3-Section Car Trunk Organizer in Black, model no. OC-105, for $7.99 with free shipping. That's a buck under the lowest total price we could find for a similar trunk organizer. It features an outer mesh pocket and can be collapsed down for easy storage.
Update: As a reader found, 13Deals offers it for free plus $4.89 for shipping.