How 'bout a 'Shutdown PC When Done' option on the MAIN screen, instead of in the advanced options? Many times I like to run CC while still doing things, so going in to uncheck that is annoying.
You can also create an individual shortcut to have it automatically clean then automatically shutdown using a command-line parameter, as seen here:
http://www.piriform.com/docs/ccleaner/advanced-usage/command-line-parameters
Essentially you'd create a shortcut with this in it (making sure the path matches where it's installed on your system):
"C:\Program Files\CCleaner\CCleaner.exe" /AUTO /SHUTDOWN
Then you'd only need to name the shortcut accordingly, example:
CCleaner (Clean And Shutdown)