Hi. I just got a brand new unopened iPod 15GB (3G) for my birthday. I also got an exo2 iSkin with it. Eventually, I will have an iPod wired in my car (ford focus zx3). My question is, should I sell this one on eBay and upgrade to the 20GB new model? I only have about 7GB of music. Or, should I use the money for better speakers/deck? Thanks.