difference between inner and outer rear wheel wells?

snapetwo said
OK, maybe I am just and idiot here.
I want to do a mini tub on my dart. I came across a post where a guy used replacement well housing and just welded them together, versus fabbing.

I found a site that sells wheel wells,
http://www.mattsclassicbowties.com/contents/en-us/d1884.html

But I am confused on the difference between inner and outer.
I am looking at the dart now, and I see a rear well, its under the car...so to me that means inner.
Aide from that it is the fender.

Am I missing something?

The rear wheelwell consists of two pieces. Inner and outer. The inner is the piece that you see in the trunk near the floor and where the hinge support welds to. The outer is the one inside the 1/4 panel. The outer is welded to the wheel lip of the 1/4.