I am considering upgrading my Comand in my B Class, it is currently an NTG2 and I am thinking of upgrading to an NTG2.5. Anyone know what is involved, I know it's not just a straight swap over as the Bluetooth is onboard rather than a seperate box as it is on the 2, but what else s involved? I also have a 6 CD changer in the glovebox, which I beleive will become redundant.