question about double din cd player for AU2

[BFD83]

i have been considering getting a new cd player for my AU2 XR6 and i rekon just replacing the old double din with a new one that has mp3 playback (which i think everyone needs!) but a couple of weeks ago i was at jb hi fi and the guy that i spoke to said that no other double din cd players will fit in the au's? is this true or he is just full of it?