Took it to the dealer today with the reboot loop easily reproducible, and it's now fixed. For anyone else encountering this, here's what they did. (BTW: No charge, covered under warranty) TSB-0041-23 VERIFIED HEAD UNIT KEEPS REBOOTING AS PER TSB-0041-23, DISCONNECTED THE AUX BATTERY FOR MORE THAN 10 MINUTES. REBOOTING HAS STOPPED. UPDATED HEAD UNIT SOFTWARE FROM VERSION 1473 TO VERSION 1586. Here's the TSB T-SB-0041-23 Toyota Technical Service Bulletin Before I brought it in, the Toyota App in the Software Update section said "Your Software is Up to Date. There are no software updates at this time". So I'm not sure why I wasn't already running the latest version. But I do worry about the future when the warranty is over, the service advisor said that the customer is able to download and install software updates themselves from Toyota's website. I think this is the site he was referring to Home | Toyota Software I think the head unit is also able to download and install updates through it's cellular internet connection, not sure why it didn't do that or notify me of an update.