My OEM plastic piece under the bumper fell off from scraping so I bought a home depot lip today, bought outdoor 3M tape (10lbs red) annnnnnnd the tape will not adhere to the lip..

Not sure if they changed the rubber compound. The lip seems kinda airy so the tape is not sticking. FML

And I thought this would be the easiest thing I could do not my car...

 

They changed the rubber so tuners cud stop mis using it for this application.

 

That's funny... I went to home depot today and found the rubber garage seal. Only found that 10lb scotch 3M tape that I'm sure you're talking about as well. Same issues. Won't stick. I ordered some automotive acrylic foam tape online. Supposed to be a stronger adhere. We'll see in a few days. If not, I'll have to abort this mod. Cost of tape will be more then its worth lol

 

I found that super gluing the 3m tape to the strip works well. The gel super glue.
Depending on how scrapped up the under side of your bumper is it should adhere with just the 3m tape to the bumper no problem.