I didn't use any additional adhesive and it is still there. I used chlorinated brake cleaner to degrease the area prior to installation and that was all it took.

I'd love that stuff except, I really don't want to drill more holes into my car. I already had to do it for the roll bar and to fix the rear sway bar struts. Any more is just inviting rust...

Ah okay, just realized that your stuff comes with a TON more of it too compared to the thermotec. If it works/worked well enough for you on track... I'm sure it's never going to give me trouble on a street car.

Thats how I did mine originally and had a few pieces fall off. The 3m adhesive spray was less then $10 and easy to do. So it may not be needed in all cases, but surely does not hurt at all.

I did DEI on the Red Car several years ago (build thread link: https://www.miataturbo.net/build-thr...6/). Still there and doing its job well. For any of these stick-on solutions, degreasing is key. I can't remember what I used, but brake cleaner would certainly do the trick.