Yeah, moving the CD changer somewhere else does sound like it might work and allow you to keep the navigation system. Does the navigation display pop out of another din unit or is it somwhere else conmpleetly? From the looks of the pictures i'm finding, it's a pretty tiny car, so I'm not sure where everything would fit... The only other problem I can see is that you don't know what interface the CD changer uses... If it's something computer derived like an IDE interface, you can't extend that cable to far...

Matthew