I've set myself the project of upgrading my concert III setup to an MMI 3G Nav plus (over a year or so). I've started collecting the kit I need to do a retrofit and have got the 3G high console and an 8T2 035 666 H main unit which is new and unused. I'm concerned the cost of getting the main unit activated(?) and up to date maps loaded will be extortionately high, plus I don't know if the HDD isn't blank and in need of some extra software. I've seen map updates of around £200 which is painful but possible, although I would probably ditch the project if I have to spend much more money on software. Am I looking at a huge bill just to get the main unit/nav working? Would it have been better to buy a used unit?