The black bracket looks like my factory installed CD changer.
The first picture of the CD changer in the softcase looks like the factory install. The softcase slides over the CD changer (acks like a dust cover), since there is no bottom to the softcase the wiring comes from the bottom.
I would send you pictures, except my digital camera is broken. The CD changer goes in vertically in the "little pocket" on the drivers side trunk with the CD drawer facing the rear of the trunk. The two tabs on the bracket rest on the raised portion of the trunk and are held by screws. The softcase slips over the CD changer. If the mounting holes don't line up then you might have to drill and tap new holes.
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles