Putting on the T/A decal that goes on the rear spoiler.
Do you install in wet or dry?
It seems some decals say to spray area with soapy water or windex.

What’s the best way to get this to lay flat with minimal bubbles?

Thx

Personally I’d always use application fluid, it’s cheap insurance to be able to position it as desired.

Place it on the spoiler dry with the backing paper still in place to be sure you know where exactly it goes, I use tape to butt to the edges of the transfer paper to control up and down and when I get the side-to-side correctly positioned I make a pencil line across the transfer paper and tape. Now when you’re ready to remove the backing paper and place the decal you’ll place it exactly where you want, apply application fluid to the decal and the spoiler, place the decal, then start squeegeeing to remove the fluid (carefully)

I worked at a sign shop and anytime the vinyl was small enough to handle I preferred to apply it dry. Just tape the transfer paper where you want it to go as once it's down you ain't moving it.

Glass cleaner works good as does water with a little soap in it.

Thx for the responses, I went the dry route because the surface of the spoiler is rough and didn’t see the decal sliding around.
Pretty good instructional video helped too.

https://youtu.be/ItodhIEVWT4

Good to hear you got it handled.

A liquid solution under a decal has it's advantages, but it can also cause the dreaded bubbles if it's not squeege'd out properly..