As part of my last service appointment (LCD screen was getting replaced because of the delaminating "leak" problem), I had asked about the possibility of installing the LTE upgrade on my 2012 Model S (CPO). The technician later texted me and said it would be a $500 upgrade, and asked if I wanted to have it done. I told him that it was okay, and that I would pass on the upgrade. When I received my car back, I saw that they went ahead and upgraded me to LTE anyways without charge! I haven't really noticed a massive improvement in speed/performance in normal use of the audio steaming and navigation, but all the same, it was a a very nice (and unexpected) gesture by my local service center, and further cements my loyalty to Tesla and my local service center.