I did a flame kit on my wifes PT and the 69 style stripe on my 68 Barracuda.

The flame kit came with some special lube to spray on the surface of the car to allow decal to move around. It didn't work to well, likely just what an experienced person would like but I would rather have it take a lot longer to set up but be easier to move. On the PT I used a few drops of dish soap mixed into the water sprayer to lube the surface.

The cheap vinyl bondo applicators work good for smoothing out the decal and for getting the bubbles out.

I used a grease pencil to make some reference marks where the decal is to be placed. I then taped the decal to the surface along the top so you can flip it up with the backing still in place.

A helper is really important. Have your helper lift the decal while you wet the surface then start to peel back the backing sweep the decal down from the center out as you move along the surface. If its not laying right lift it off or just slide it around.

REAL IMPORTANT: If the decal has a waxed paper like backing DO NOT get it wet. I learned the hardway and ruined one of the flame decals. This stuff turns into little balls of gu that you can't clean off the decal. Luckly the outfit I purchased the kit took some responsibility because they didn't mention that in their directions and sent me another flame decal for that side of the car.

The one I put on the Barracuda had a mylar backing, and there is no issues if you get it wet.

Once in place let it sit for an hour or so before you try to remove the top cover. Peel it back on itself.

If you have small bubbles (1/8" or smaller) don't worry they will disappear on them selves in a day or two in the sun. Bigger one you need to work out before the water drys out and the decal is adhered.