Its really up to you and what you want. The two main points you want to aim for is that when the insulation is installed, the door must still be able to open and close. Second is that the doors will get very hot all day and then when you open the door, it would be best if the panels stay IN the door instead of falling on your head and vehicles. With that said, if the door works fine with the panels beyond the face, let it go if it doesn't bother you. With the heat, I'm not sure the taping would be the main method to keep the panels in the door. Also, tape has a life span that is less than the eternity. I picked up a couple tubes of the Loctite Heavy Duty Construction Adhesive to install the blue panels in mine, but it will be a couple weeks before I can get to that project.