GM appears to have available for earlier CTS models (through 2007) a DVD screen in the back of the seat headrests.
http://cgi.ebay.com/ebaymotors/05-0...6aQQitemZ370046815082QQptZCarQ5fAudioQ5fVideo
Perhaps that can be adapted to a 2009 model?
http://cgi.ebay.com/ebaymotors/05-0...6aQQitemZ370046815082QQptZCarQ5fAudioQ5fVideo
Perhaps that can be adapted to a 2009 model?