kpalmal - I think this is only a feature on the 2007 Civic. I tried this again tonight on my 2006 after reading your post and there are two discrepancies: 1.) the manual does not mention a section on "unlocking all the doors" but just the Driver's door and 2.) there are no more clicks after the one at th 5-second interval. I tried every possible combination (holding in the Unlock button, pushing the unlock button twice and holding, etc.) and no setup was successful in unlocking ALL the doors when putting the car in Park or turning off the ignition.

This is another feature of the 2007 model along with the Scan function with the steering wheel audio controls. *sigh*

--> Averaged 685 miles/week and 49.0 mpg in first year (35.7k miles from Aug 7, 2006 to Aug 7, 2007)