2005-2007 MPS6 are all the essentially same except for the very minor mods already referred to above. There were only two versions offered each year, the options being either velour trim or (leather trim + Bose stereo + moon-roof). You should have the under-pan shroud. Some twit has left it off. It helps control airflow into the engine bay and under the car, reduces form drag and keeps your engine clean. I could care less about whether mine has or hasn't got MP3. I prefer the sound of an engine on-song.