I've had this issue on 2 occasions now, once pre- and once post- Version 9. After being away from my car for several days, on re-entering, the MCU was entirely powered down and I had to go through several reboot attempts using the scroll buttons to get it to come back on. During the MCU reboot attempt time, there was no functioning AC/fan, etc., so sweltering inside of the car for several minutes while waiting for it to activate. Because I was unable to pinpoint the exact time of the failure beyond a 2 day period (since I was away and only recognized the failure when I returned), Tesla was unable to demonstrate the failure on the log and would not declare the MCU to be faulty. Anyone else with this experience?