One month ago, I posted a thread in the Model S forum about my Model S HW3 upgrade experience at the West Palm Beach FL service center: https://forums.tesla.com/forum/forums/my-hw3-upgrade-experience-west-pal...
My wife's 2018 MR RWD Model 3 was just upgraded to HW3 yesterday (Thursday), also in West Palm Beach, but this time at the new location on Okeechobee Blvd. Both upgrade experiences went pretty well overall, but the Model 3 upgrade didn't go quite as smoothly as the Model S.
As with the Model S, I wasn't notified that the upgrade was available. I was following up with my service advisor about the Model S upgrade and asked her to check if the Model 3 upgrade was available, and she confirmed that it was and asked me to schedule an appointment in the app, which I did. My appointment was for Wednesday (2 days ago), and the work was completed the next day (the Model S went in on a Monday and was done Thursday morning).
For the Model S, my service advisor contacted me the day before the appointment and told me it would probably take a few days, and she also told me they wouldn't have any Tesla loaners available (but they would an ICE car). For the Model 3, I didn't hear from anyone before the appointment, other than the automated text message appointment reminders. When I dropped off the car, my advisor told me it would probably take a few days again. This time I chose the Uber option rather than a loaner. I was expecting to get an Uber credit, but instead service actually set up the Uber ride in both directions, and I got updates on the ride status via text messages (don't know if all service centers do it that way).
Yesterday afternoon, I first received a text message saying the car would be ready this morning (Friday), but a short time later the advisor texted me to say the car actually went in the shop a couple of hours earlier and was ready to be picked up, so they sent an Uber to bring me in.
When they upgraded my Model S, I didn't lose any settings at all. For the Model 3, I only lost my WiFi and Bluetooth phone pairings (the phone keys were still set up), and I noticed the Stopping Mode in Controls Driving had changed from Hold to Roll, so I changed it back. As before, the Controls Autopilot FSD Visualization Preview setting was disabled, so I enabled it. Note that the preview setting is saved in the driver profile, so you need to enable it for each profile. After fixing the settings, I rebooted for good measure.
While they still had the Model 3, I received a software update complete notification from the mobile app. When we picked up the car, they had downgraded the firmware from 2020.8.1 to 2020.4.1, and I'm pretty sure the navigation data was downgraded also (my Model S didn't get downgraded).
Neither the Model 3 nor Model S required any calibration before I could see the new visualizations and use AP. If service calibrated the cars, they didn't do it by driving them, because neither car was driven more than a couple of miles while in service.
When I re-paired my phones, I had trouble getting the new Sync Messages feature to turn on, even though my phone settings were correct. It turns out I had 2 Bluetooth entries for the Model 3, one identified as “Tesla Model 3” and the other as “Tesla Model 3 EV 3” (EV 3 is our car's name), and I was trying to pair with the first one, which apparently was no longer valid. Deleting the first and pairing with the second fixed the problem.
When I got home and restored my home WiFi connection, the car immediately rebooted, but that didn't happen again. After it restarted, I checked the Controls Software screen to see if I had an update waiting to download, and there was a Downloading Game Update progress bar. When that finished, I didn't have to install anything, and I was still on 2020.4.1, so I guess the game updates are like the map updates and don't require confirmation.
I also noticed that when I reinserted my music USB, it took a lot longer than usual to load, and after rebooting, it loaded slowly again. I usually have shuffle mode enabled, but I had to re-enable it each time the USB was reloaded. Although the USB would sometimes reload even before the upgrade, it loaded much faster and never lost shuffle mode.
That's all for now. If I think of anything else worth mentioning, I'll update this topic or post a comment.