There is a bad odour inside vehicle?

What is your question?

There is an unpleasant odour which seems to be coming from inside the AC Vents of my 2016 Jaguar XE (purchased new). I have switched the A/C full blast on cold (16 deg) for 15 minutes and hot (28 deg) for the same time - as it was suggested this may solve the issue. It hasn't. Could it have something to do with bacteria build up in the A/C vents? I would like to advise Jag prior to a service I have booked. Any help would be appreciated. Note: The car is kept pristine - and a full check of the entire car found nothing that would cause the odour.

What makes this problem better or worse?

Nothing.

How long has your 2017 Jaguar XE had this problem?

A few weeks.