worn out upper door panel

[Christian Williams <delorean@xxxx>]

I'm sure a lot of us have this problem, so I'm wondering if anyone has any
good solutions.

I've had to take my upper door panels off quite a few times, and the stiff
cardboard (?) with holes for the fir trees has become feeble and torn in
some places. I've hit upon a system where i use a few pieces of scotch
tape to hold the fir trees in the right place so that i can get the door
panels on, but the tape seems to give way and leave parts of the panel
disconnected from the door.

Does anyone know of any way to reinforce the door panel so that the fir
trees can be held firmly in place once again?

-Christian