Well after my install of Audio and stuff, I put back my Center piece (the big one with the hazard light switch and 2 cup holder) Now, I've notice that the door don't pop up when I push the button. I have to push the button with my thumb and use my index finger to lift the door up. Was there a weight or spring there??

 

There are 2 springs. One on each hinge that assist the door. They must have been forgotten. Or they are there but there is an alignment issue. It is a very close tolerance install( the lid and box) so if there is something caught between the bottom of the cupholder and the top of the tunnel, it will distort things enough to cause what you describe. Maybe a bundle of wires?