busyychild great info. It is quite possible that the 11+ WRX premium is wired for the turn signals. It could just be your car as well, we never did figure that out ;-) I see you found the thread on 3gWRX about the same thing. I was keeping track over there of which people had "live" signal wires from the factory (they all have the actual wires) but we found no rhyme or reason.
For instance my 09 premium WRX had dead signal wire. But fortunately it is about 5 min to make them "live"
which I explain in the thread on 3gWRX. Adding heat to a base is not too bad either, the dash wiring is there and you can use some unused wiring in the door.
Now let me know when you are ready for JDM power folding, most of the wiring is there in these cars for those too ;-)