I have a 2015 Model S which has gone through many iterations of UI changes throughout the years. One of the things I seem to recall was that heated rear seats was available through the app and the MCU. Granted I rarely have passengers in the rear seat and I'm in California, but it's still annoying to think that they've removed a feature that I paid for. Maybe I'm just remember it wrong, but I'm almost certain there used to be rear heated seats. I'm on a recently (laughable) upgraded firmware 2022.8.10.17.