Hi all.. Just had a COMAND NTG2.5 retro fitted to my E class. Overall very pleased with it. However I have been told by several people that my voice sounds muffled and unclear when I speak on the phone via the bluetooth link. There is a .mic fitted on the top of the screen next to the roof console (drivers side obviously). What I woild like to know is, do mics vary in quality. If so then is there a particular model of mic I should be looking for? My previous C270 cdi also had an NTG2.5 retro fitted and there was no such problem with it.