I bought these Command Clips at the Walmart in Rifle, Colorado three weeks ago while we were attending the Fall 2014 Colorado Heartland Owner's Club Rally ($10 for a pack of 20 clips):
Just slide a towel in there . . . and no more sun in the face!
I'm also going to try these clips to hold the power cord for my Rand McNally GPS unit to my dashboard.
I just wish that these clips came in black as the white sticky tape will look awful on my black dashboard.
After we got home, Cathy found some different Command spring clips at the local Walmart that we will try and report back with the result of our scientific tests!