Sorry for the bump, but I just wanted to let everyone know my bottom 2 melted after about 2 years. Here's the worse one, which actually started to slide down. I have no idea how I'll be able to clean the windshield off...
I've been having the same issue all winter. It happens around 2k RPM and becomes less frequent as the engine warms (not sure if that's related or coincidental). I haven't noticed any adverse effects, but I'm definitely mentioning it next time it's in for maintenance.
You can't change it, only extend it. From the manual:
"The engine runs for up to 10 minutes. To extend the run time for another 10 minutes, repeat the procedure during the initial 10 minutes."
I have the same noise, sounds like metal rattling against metal, from the center or driver-side rear deck. This is also my second winter with it and it only started a few weeks ago, when it's really cold.
http://www.civicx.com/account/alert-preferences
Uncheck "Persistent Alerts Enabled" (the second option). Make sure you click Save at the bottom of the page.