My 2 cents is just update the radio. I was amazed what $45 would buy you. Among other things, we also listen to audio books when driving and the Kenwood I put in plays just about any format you want to throw at it on CD. Audiobooks to MP3's. It also has bluetooth so that makes it simple to play whatever's on your phone(s). Aux input on the front and a USB port if you dump your music or audio off to a flash drive.
Of course, every installation is different, but mine was fairly simple and I ordered an installation kit along with it. Main thing it had were adapters in case your wiring deosn't match up.
