A couple of carpet questions

[loco340cuda]

I just got my new trim parts carpet for my 70 cuda. In the installation paper it mentions that I need spray adhesive.

Why do I need spray adhesive and what brand do you guys recommend? Where can I buy it.

Also where can I find the rectangle plastic pieces that go thru the carpet and give it a finished look. The pieces I'm talking about are where the front retractable seatbelt comes through the carpet. Sorry I don't have a picture to show right now.

[Moparal]

PG classics repops those retractor covers now. I see them on ebay on there site.

[JayBee]

I've replaced the carpet 4 times in my '70 and have never used any adhesive. My only guess would be they used to be glued to that plastic cover/shield that's above the retractor and under the carpet.