Well, I just researched this a little - gets even more confusing. It looks like, although the faceplate is all one big piece on all models, behind that faceplate is a separate upper radio/CD unit and lower climate control unit. I can't really tell how (or if) the LX and EX differ behind the faceplate, although obviously they do.

This is all too confusing for me - I'm just going to replace my speakers!