The top dashboard storage is really only a stop-gap design measure for models that don't have the Nav system. Yeah, it doesn't hold much. But the center console storage more than makes up for it.
Only a single CD player? It's 2010, USB & Aux are the defacto standard, and rightfully so. Putting CD changers into vehicles will soon be extinct, seeing as a $20 Memory Stick holds 10x as much music as a $500 changer. Multi-CD systems make no sense, on any level. Sorry, that's technology for you.
If you have a huge CD collection and none of it is ripped into MP3, go buy a nice bottle of wine and download iTunes. If your CD collection is that big, go pay some kids a couple hundred bucks to rip your CDs for you.
Keep in mind, the terrain/nox/srx all support USB storage devices (not just iPods).