step 1 inject glue
step 2 turn car over till glue cures

I thought about the staple thing, but overall the car is in pretty decent shpae inside and I really didn't want the look of the staples.
Gummy'* idea might work if I let my wife drive too much.

It'* not white though?

(This one'* for you Gummer)

Nope mine is blue. I am safe

Staples probably won't work. Think about it - you're stapling into old foam that'* brittle. The staples will fall right out.

I had to remove the head liner in an old 92 SSEi that we owned briefly to fix the sunroof drains. I pretty much gutted the entire interior to get it out with minimal bending. That meant I removed both front seats, the center console, the back seat, and the rear seat back. When I took it out, I only had to bend it very little. It was so little that upon reinstallation you couldn't even tell I had it out.

I am hoping that I don't have to take anything out. We'll see. On the bright side I was looking into replacing the bench seat so if I do have to take it out I'll get a better idea on how to do that.
On the Aries I did I didn't have to take anything out, but it was a bit of a pain.

Actually the staple gun shoots right through to the cardboard you so Um no.....they wont be falling right out. I only mentioned it because I have seen it done many times. Anyway if you are planning on fixing the car up you are right staples would look like crap.

Ahhh, FYI, there'* no cardboard used in the manufacturing process of headliners.

I used to work in a headliner manufacturing plant and no where in the process was cardboard one of the materials.

card board, foam board, fiber board, etc.. its all the same

No it'* not. But that'* not the point, there'* no "board" used at all.

It'* layers of fiberglass backing, foam, cloth, and glue all pressed together in a hydralic press against a die that resembles the roof of the car.