Is it correct that the 06+ stock head units, which have mp3 capability, do not sit flush when installed in an '03?

I want mp3 capability in my '03 (non-bose) but I do not want to change the stock look much, and most importantly I don't want to have to worry about theft. Anyone have any ideas (with pics)?

I basically want an OEM unit out of some other car (Nissan or not) that supports Mp3 and looks 'right' in the radio spot.. I can handle the wiring..

Thanks

 

I always thought this head unit was really clean

Pioneer FH-P8000BT

 

^ That is hideous and also will not blend in with the blue buttons and the silver ****. The aftermarket ones stick out if any like a 8th of an inch or so. The kenwood 6140 looks rely nice in the dash and blends in fine.

 

Wow, that's actually really nice!