Forester - generic brand back cage - safety issues - success?

Hi - has anyone found/used a cage between the back seat and back cargo space on a Forester not made by Subaru? Success? The brand name one is quite expensive. I'd like to have one for safety reasons - if I was to have an accident, I don't want my groceries or other cargo flying around the car possibly causing more harm than the accident itself. Any advice would be appreciated. Thanks