This Eonon unit comes with the CANbus decoder and as stated its needed for the steering wheel controls to work.
The I-Bus adapter is available from third parties and along with the I-Bus android app gives you access to function lost by removing the MID unit, i.e. resetting the time/date, mpg readings etc. The I-Bus app can do lots more also, as I'm sure you're aware.
*edit* oops - I'm just repeating what OB said - let's just say OB is correct!
