A good way to get the dealer to code the TCU is to call in and say you want to change the sound of the siren for the alarm, or to change your fogs to come on when the headlights come on. Then just when you get to the dealership for your appointment, mention that you also want voice commands enabled while they are messing with the settings. I have heard stories of fanatics who tip the service advisor $20 and the advisor brought them to the back and let them hand select which things they wanted switched on or off. Worth a try IMO. Good luck either way.