I added a 3rd key to my 2014 Sport when I bought it using this method. I then purchased a RF blocking pouch (Faraday cage) and hid the extra key in a hard to reach place within the car. So if I ever lose or damage my key so it is unusable, I can just enter the code on the door key pad, take the hidden key out of the pouch, and be on my way. I also recommend the 3rd key in case you lose any of your keys, this way you will still have the required minimum 2 keys needed to program a new key without having to go into the dealer.
My cousin found this out the hard way when she lost her key when she was out of town, then a few months later her kid started playing with the last key she had miss placed it in the toy box. They were looking at a $600+ replacement cost from the dealer plus the cost of the tow.
