Thanks Steve, really appreciate your prompt response!
Apart from the inconveience of not having any music/satnav, it is going to be a bigger issue come MOT time as I also had a tyre changed (puncture) and although it is now fine, I can't initialise the tyre pressures as this all done via the MMI computer so showing as a warning on the dash that I can't update.
Next question...is the recoding of a replacement MMI unit sort of thing a 'local' specialist could do or would this have to be done by an Audi main dealer?