I am considering buying an Empeg for my 99 Mustang. I did a search of this forum and a few things turned up that got my attention. First, someone said that the interface between the CD player and head unit is proprietary, and that connecting a CD player to the Empeg would be difficult or impossible. Can anyone verify this? I would really like to keep the ability to play CD's on occasion. Also, if anyone has any general notes on what they did with their Mustang install, or things they ran into, I'd love to hear your stories.