So, I didn't want to pay $50+ for a trunk mat for my new 2011 Sportback so I poked around the internet and found an article that suggested a $18 floor mat from Home Depot. Turns out that it's a perfect fit and there's enough left over to stash on top of the spare tire for use when the seats are folded down.
I used an Enviroback Charcoal 60 in. x 36 in. Recycled Rubber/Plastic Rib Door Mat.