Just bought a 92 z28... someone had tinted the rear window but now it looks like crap and i want to strip it. Some of it pulls off, some it stubborn, It looks like there is 2 layers, a lighter and then a darker tint on top. Ammonia works on the adhesive but does anyone know any tricks to getting the film off? I don't want to razor scrap the whole window as I know I will damage the defrost line on the glass.

 

hairdryer/heat gun

 

There are some threads about this if you search. I've heard soaking it with ammonia and then covering it with a dark trash bag on a hot day for 30 minutes to basically bake it. And then tearing it off in one fluid motion. I have yet to try it on mine as I also dont want to mess the defrost lines up.

 

I think you will have to just keep what you are doing. That method works the best in my opinion. I have lots of experience with tint. I just pull off the tint and soak the residue with finger nail polish remover. That has always worked the best for me. Good luck!

 

Just removed the old tint on my 89 IROC last weekend. It took time but wasn't difficult. The link below has the instructions using a steamer. I used a plastic putty knife to help keep the tint layers from separating without damaging the defrost lines. The side windows came off in one piece and the rear window came off in two. After the tint is off, use rubbing alcohol or mineral spirits to clean off remaining glue residue.
http://www.instructables.com/id/How-...messy%2c-chea/