If you want factory style bluetooth music streaming with a 2011, you need to replace the PDIM. I don't know if it will work if you have nav, but if you have the standard radio it will probably work. The model I put in is ACDelco 22797218 Multi Media Player Interface Module Assembly. I looks like there is one for sale on eBay. With this module replaced, the directions in the thread you mentioned should work. It's been a while since I did this, so I think there was a condition that the software version of the radio be at a specific version and mine was at that, so I don't know if it will work with other versions.
This thread has the directions I followed. They are for the cruze, but it worked for my equinox. DB/DD is the radio version I have.