This is probably obvious to everyone but since it took me four months to figure it out I thought it might help the engineering challenged.
I could not decide where to store the parking card I use every day for the lot at work. The glove compartment was too tricky to manipulate while opening the window, avoiding the gate, and not delaying the line up behind me. I tried the door pocket but then it would slide around when accelerative forces were applied too vigorously while maneuvering. In a tight turn, I would hear a noise, and have a half second of fear while remembering what the noise was.
The answer is, as usual, the simplest. I still keep it in the pocket, but now I stick it in vertically up against the inside of the pocket wall. It slides down into a crack at the bottom of the pocket and is held snugly up against it. It doesn't move, it is hidden, and it is easy to reach down with my left hand and slide it up. A permanent solution to a trivial problem.

I always stick parking cards/highway tickets etc in the visor. There's the little slot for stuff like that, so it works out fine. Unless you're worried about someone stealing it of course. Depends what the card actually is I guess.

But sounds like a good solution for yours so its hidden.

The best place (although it is visable) is to squeeze it between the top of the speedo and the dash or in the bottom corners of the speedo and the dash.

My parking card is the RF type (contact-less), so I'm able to keep it in my checkbook, in the door pocket. The leather cover means it doesn't rattle around (or at least, doesn't make much noise).

Chip H.

I still keep it in the pocket, but now I stick it in vertically up against the inside of the pocket wall. It slides down into a crack at the bottom of the pocket and is held snugly up against it. It doesn't move, it is hidden, and it is easy to reach down with my left hand and slide it up. A permanent solution to a trivial problem.Thx for the excellent tip, shredder; it saved me the time and trouble of doing the experimentation myself!