Lose the rubbermaid container, while the products are well made slick isn't a good thing on something you wish to stay put. As someone else mentioned an eggcrate is a good way to go or use a container that has a similar grid patternon the bottom. I use fold up containers that have a grid on the bottom in the carpeted bed of my pickup and i don't have any trouble with it moving around. Also heavy cloth like a duffel or parachute bag if placed on carpet tends not to move around. And if you put something heavy like a floor jack in the trunk be sure you tie it down.

The other option is to get a car with a smaller trunk, when i put a BOB, FAK, camera bag, and tool bag in the trunk of my Miata i don't have to worry about anything moving around because the trunk is packed.