There is complete integration in some newer models that I would leave as intended from the factory. There are owners that think installing the newest, Biggest, systems are better( at least it may make you feel better) If one can afford to tear out an audio system from a new lexus and replace everything IMHO they are throwing there $ out the window. The $ is better spent on a system for ones home. Consider road noise, Music genre, CD/MP3 quality, Radio Reception and many other variables. My.02 cents