Here's a quick look at what you can do with the Anker extended battery/case and a bumper...
Before
After
Carbon Gear is where you can get one.
They are a little more expensive and I'm sure you can ebay it but I live not to far from where Carbon Gear is at. It ran me about $15 shipped maybe a little more but it was around there. On ebay you can search for "3m Vinyl carbon" and you should get a ton of hits.
You'll need Patience, an Exacto knife, scissors, and a hair drier. Mine came out almost the same as the posts above, he just beat me to the punch. lol
1. The Patience is self explanatory
2. Put the sticker on the case, make sure to cut more than you need for "shrinkage", I gave myself about an inch or 2 on all sides.
3. Use the hair drier to form the sticker around the edges and nooks and crannies.
4. When satisfied let the sticker cool off and use the exacto to cut the excess off.
This is easier said than done but if you screw up a 12" x 12" sheet should give you enough to do this three time. I got it on the first time and my only advice is to take your time. This is the best way to do it because no one makes an extended door in patterns yet nor can I find a back door by itself.
I would also recommend not using the aluminum bumper with the rubber buttons. While it does work it's a super tight fit and while adjusting the front sliding frame I ripped off my JLG protector. Luckily my MIME SP just came in the mail today. ROFL.