It’s called permanent mounting tape, but it doesn’t have to be. Here’s the right way to remove the tenacious double-sided foam tape that’s often used to mount dashcams, phones and the occasional vintage GPS navigation device.
First, don’t use brute force. That’s exactly what this kind of tape resists and you’ll probably just break the mounted device, windshield glass or top of your dashboard if you just yank on whatever’s mounted. Instead, use permanent mounting tape’s one weakness: Patience.
Start by liberating one corner or edge of the tape from what it’s stuck to. You can use a single edge razor blade or dental floss under the edge of the taped object to do this.
Then slowly pull at the object to start separating it from what’s stuck to. If you pull the tape fast it will resist and either tear itself or whatever it’s stuck to, leaving a mess or expensive damage, but an infuriatingly slow pull will convince it to let go cleanly. If you’re not annoyed, you’re not pulling slowly enough.
If you’re just removing raw tape from a surface here’s an additional tip: Liberate a corner of the tape as above, then use a very shallow angle as you slowly pull it off. It’s similar to the technique used to remove Command adhesive products. That product relies on an unrelated stretching action to remove it but the low angle of removal also helps with permanent mounting tape.
By the way, a technique that doesn’t seem to work is heat: Warming up permanent mounting tape with a hair dryer only seems to make the substrate stretchier, reducing the leverage you have to separate the adhesive from what it’s stuck to.