I recently took my 2014 A-6 in for service. I asked the desk if there was an update to the MMI software since it was over a year and half old on my car to date. The rep say yes but there was a charge to do the update. What?? Why do they offer a tech feature on a car and then ask the customer pay for an enhancement made after the car was bought?

 

You basically answered it already - it's a feature not a required update to fix something that is broken or not working correctly.
If the update would resolve issues (black screen, imaging issues, etc) they would offer it as a recall or free upgrade. However since they only add or improve on features - they want to see money.

 

Whenever I have upgraded the Nav discs in any brand car I have owned, there has always been a charge for the upgrade disc or software.

IMO, the charges have been too high a price for the amount of new information contained from one version to another.