i'm sure that my bose on my 2006 didn't had any security codeI did not like the display the 2005 radio has. This is a brand new 2005. By changing, The display now matches the instrument panel (yellow). one thing else is the 2006 has mp3 and no cassette. I would never use the cassette. I got the z at a good price and it was brand new so I figured I would do some mods since I got a good deal. I will have a brand new 2005 radio for sale shortly. From what I am understanding there are no security codes to worry about, dont know why the dealer asked me if I had it.