Learn The Hard Way: Razor On Inside Back Window
I got a razor blade (in a holder) and started to scrape it off as much as possible to be followed by some solvent to get the rest.
Guess what happens? This _should_ be in the manual somewhere as a warning:
Razor blade will scrape off the heating element! .
Nice huh?! I think I ruined two of the little rust-colored elements that run from port to starboard. The rest of them should still work though.
Don't make teh same mistake: NEVER use a scraper back there!
DAMMIT: the inconsistency (thinned and irregular line) is now VISIBLE when you look at it from outside the car!