It's probably the hardest thing for me to clean and I can NEVER get is smudge free - back window especially. What does everyone use to clean the front & rear windows? I've tried using the Eagle 1 20/20 but it seems to act like more like a wax as it takes a LOT of wiping with the newspaper to get all of the solution off. Plus no matter WHAT I do the back glass always has smudges in the crevaces where my hand can barely reach. Is there a tool I can use? Help!