after 1st hand experience, hitch racks are over-rated. I just got one of these for wifey's Toyota matrix. it would work well on my 2011 Forester, and probably any year. I have an older model that pretty much fits the same way, resting on the back bumper and held on at 6 points with straps hooks. tie a knot at the strap fastener with the left over strap and it won't loosen.
http://www.amazon.com/Hollywood-Rack...449080-0258634
here are some others you can consider
http://www.amazon.com/TRUNK-MOUNT-CA...449080-0258634
http://www.amazon.com/BuzzRack-Skipp.../dp/B004JKUDNQ
http://www.amazon.com/SportRack-SR31...im_sbs_auto_21
http://www.amazon.com/Trunk-Mounted-...im_sbs_auto_48