You will lose the steering wheel buttons, however someone told me recently there is something for about $300 US that can get those controls to work, thats of course without installation. Secondly, I purchased a AVIC-D1, and im assuring you that you wont be happy with the look of it. Sure it might have more functions (However, no DVD playback in the D1, not even with the parking brake on) but I would suggest a BMW system in there, im totally regretting it right now.