Interesting. I had the exact same issue with my 2013. This slight rubbing/whining noise was starting to get worse and would increase in intensity after driving for a bit (or when it was a bit warm outside/inside.) It sounded very much like a piece of plastic rubbing against another plastic piece and felt as it was coming right from underneath the steering wheel and not from anywhere deep inside.
Dealer kept it for a couple of days, coudn't figure out the fix/diagnosis, and then they talked to the factory and finally replace the steering column (lower I think). I picked up the car recently and so far so good. Shop foreman told me that there was a TSB on earlier models for a faulty seal inside the lower steering column, and that back then factory advice was to just replace the seal only. My car was obviously not in that vin range. And this time factory advised them to replace the entire column.
I was kinda surprised as the noise sounded like that it could easily be fixed by doing exactly what Count and David have mentioned here. Its funny that I didn't even know about this thread up until now (after I picked up my car) but I said to the shop foreman the same thing as above, to which he replied that sometime noises may sound like that they are coming from places which are not the real area they are being generated from.
Anyways I am just glad that its fixed.