Will the iPad eventually replace the entire MKiv? iPad in double din. Just have to hook it up to the amplifier (over the iBus, perhaps even feeding via SPDIF?). The cheapest solution is just to hang up iPad on a cord and connect to AUX No need to replace your existing unit, just "hang" the iPad over it..

You will lose:

• OEM Navigation + indication in dashboard
• Radio
• CD / Tape / MD in dashboard
• CD Changer (optional)
• TV module (optional)
• Bluetooth installation (optional) - guess you could still use voice dail if you do not remove the MKIV
• Vehicle settings, but then someone could code an iPad app that connects to the iBus via the USB to iBus connector and create a nice BMW app
• Steering wheel controls - only volume up, volume down would work. Perhaps an app interfacing with the iBus could resolve this?

You will gain:

• Latest navigation software, including lane assist, traffic info (over 3g?), realistic road signs
• Full touch screen
• Full HD video quality
• Radio streaming over 3g

Remarks:

• You will need the 3g model in order to have aGPS, unless you use a bluetooth gps dongle.
• The Apple cover seems to be pretty good.
• Now just have to be patient and wait for a front-facing camera.

Exciting!