I posted a couple of photos of what I have in my trunk. I tend to build a "box" to hold certain things in the trunks of my cars. When I change vehicles, it seems that the old box never fits the new trunk, so a new box is built to the specs of the current trunk. In the photo, the wooden box has places for storage of 30 and 15 minute flares on the top shelf along with a fire extinguisher. The shelf these items are on is slanted so that the things stored do not fall out when the vehicle accelerates. Also, the fire extingusher is on a rubber mat that is sold at home stores for working with wood, it acts as a non-skid surface and is sufficient to hold the extinguisher without a vehicle mount while at the same time making it easy to remove. The bottom portion is for storage of general items, the idea being building "up" to take as much advantage of the limited space as possible.
The boxes in the trunk, plastic and metal, have industrial grade velcro fastners on two of the bottom corners that help hold them in place when they contact the rug material in the turnk of the car. You can pick up the fasteners (looks kind of like heavy artifical turf) at the Home Depot. I have used the common version of the velcro fastners and found that with heat, the velcro tends to come off the box and actually melts the sticky tape into the rug. Not good!
The velcro does not stick well to unpainted wood, so for the box I built, I put a small brad in each corner and cut it off at about 1/16 of an inch. This tends to hold the box in place with the rug of the trunk.
The contact is sufficient to hold these items in place, but given enough force, I am sure they would all break loose. As of this time, I have never had any of the items shift in the trunk, so it suites my needs.
If you want to try the velcro fasteners and are unable to find them, let me know and I will be happy to send you some.
Trunk Organization