ION boxes and inserts

Couple of questions about the ION:
1/ Under the car behind the back axle is a large rectangular box. Anyone
know what this is for? (The fuel tank is in front of the back axle)
2/ In the instrument panel next to the hazard light switch is an insert that
carries the ION name. Anyone know if this insert covers an opening that was
for an abandoned feature, such as a display (clock, temperature,
orientation, engine parameter, that sort of thing)?

 

That box in the rear is the charcoal canister for storing fuel vapors.

I'm not sure if the dash insert originally had anything else. However, on
vehicles with ABS/TC it also houses the traction control disable button..