Very nice tutorial!

Just need some adjustments to run @ Ubuntu/Mint:

sudo crontab -e (You need to use the cron of root to be able to use @reboot)

The correct syntax of the command should be:

@reboot sleep 30; /path/to/your/auto_start_script

The "sleep 30" is needed to give enough time to let the OS mount the device where is the user script.