My reply has to do with removing old tint. I had to have the rear glass and front door windows re tinted on my dd due to a previous owner using limo tint and you literally couldn't see through it. I talked to several tinters and they were sketchy about pulling the old tint off the rear glass and harming the defroster elements in the glass. Then I found a guy who knew how to get the old tint off without scraping. He simply wet it down well, taped a plastic garbage bag over it and let it sit in the sun for a good 15 minutes and it lifted off in one piece. So now onto my six. I don't know if it's from the rear defroster or just 40 year old tint, but at night lights from behind and a car itself show in my mirror as coming through the glass in quarter sized circles so that will be redone Bottom line is find the best tinter you can and yes re tinting with the glass in the car will not pose a problem. I do not have an adhesion problem I am aware of as the film seems to not be bubbling