Yeah, that is my favorite place, but with the rods that connect for the trunk and the forced air rear window defogger, I can't install it on the package shelf. not really any other good place that is not in the way. Thanks though.
You can usually install those changers at a variety of angles without affecting their performance. Check the install directions. I saw one mounted sideways on the trunk support. On my 86 Regal, I have a CD changer, amplifier, and Bazooka tube mounted on a piece of Fibreboard that I screwed to the trunk floor directly under the package shelf.