I have one in one shop; reading this thread, I think I should have one in all three. One use is pulling dents from fenders. Another is any kind of plastic housing that has a crack in it, especially electronics under the car hood, plastic gets brittle after 2-3 decades of use. Anti-vibration anchors for wiring is another use. It can be cut or removed with a heat gun if you need to service it later.
I agree with Thumper68, cheap hot glue for when you may need to take it apart, just use a heat gun (industrial hair drier). While all crafts store glue sticks are marked "high and low heat" they are all low heat. When you get into high heat glue sticks you're on a whole nother level of stick.
3M makes all kinds of glue gun sticks for every material and purpose. I have 2 or 3 types already, including black, which I bought just to hide the fact that I'm using a glue gun. Also craft knives and sharp scissors help clean up the hairs left behind that scream "I just used a glue gun".
Funny thing, just got back from a fair this weekend where one booth had crafts covered with glue gun hairs. Geez its takes a few seconds to trim them off once cooled. Have some pride in your work, huh?