I went to my local service and they told me it wasn't possible to go from SR to SR+ which I knew wasn't accurate. I called Tesla support who gave me an internal document number of 53611 which describes the entire upgrade process and how to do it. I took that back inside to the service center and they still told me they had never heard of it, but would look it up and call me back. I didn't have much faith that would happen so I called yet again to Tesla support and they called a "more experienced" service center who ran my car and got the numbers. They said I can buy autopilot in the app for $2k and then the upgrade to SR+ would be $2k. I asked for an email stating that price but they said they couldn't do that and instead would get the service manager for my local service center to contact me. I'm not buying yet until someone can generate the SR+ order immediately after I add autopilot because we only have 48 hours to request a refund if that extra $2k ends up not being the case. I started my journey with a 2014 S85 with AP1, then my wife bought a LR RWD 3 when they were released, and then I swapped my S for the SR 3 last summer. It seems to be a crapshoot in regards to getting a straight answer from them on pretty much anything. I can't imagine a first time owner dealing with this sort of runaround.