I have a Sony 10 disc CD changer mounted in the trunk. I placed it off to the left and far enough over that I still had access to the little cubby that is all the way over on that side. It is mounted horizontally with the opening facing into the trunk. I needed to face that way so I could access the disc magazine. It turns out that there is a major disadvantage to this arrangement. The newer Miatas have a relatively flat trunk area and because it is a sports car, turns are usually taken with elan. This combination results in anything that is placed in the trunk sliding around. When everything slides to the right it is stopped by the inside fender well, but when that stuff slides left it gets stopped by the CD changer. It is mounted very sturdily, but the plastic disc magazine door is taking a beating.
It is like most changer doors in that it is a convoluted two-piece sliding thing. A few weeks ago I got tired of popping the small door back onto its tracks, so I got some household cement and glued it in place in the big door. This was great until this past weekend when I went to put my MP3 Christmas CD in. Those doors are in two pieces for a reason and that reason is so that they open wide enough to allow you to get the magazine out. Oops! I had to stretch the big plastic cover out of its tracks to get a big enough opening to change out a disc. Today I must have got a direct hit with a sliding lunch box because the little door came uncemented from the large one and was floating around the trunk. The small door is stuck in the trunk cubby for now.
I can move the changer to vertical so the stuff bounces off the side instead of the face, but then I lose the vertical space above the changer, which in the current full trunk scheme is reserved for the small cooler. This is undesirable option. IIRC mounting it facing the other way left no room to swap magazines. This option requires investigation. I probably shouldn’t just leave the door off because trunk projectiles may damage some important internal mechanism. Another option might be to rig up some sort of hinged or quick releasable partition. Is ditching the changer an going with satellite radio in the future?