It was after a week of my wife driving the Q7 with her own key.

Any ideas?

because its the unlocking that activates your settings even if its already open.
If you lock it after use but she opened it, your key will then store her settings.

Just a thought.

that my station tags will be lost?

Cause that's the story.

your key will save your new settings...Hers.
Just try it, no harm.
It happened to me once doing the groceries. She got back to the car first and unlocked...everything moved to her presets, seats mirrors, heating and frequently used stations. I hopped in put my key and started car, then we remembered something got out and I locked the car losing all my settings.
Ever since I just hit unlock before using my key.
Its fun watching the seat and mirrors move.

It's a pain cause I tend to have the maximum number of station voice tags saved.

Thanks again,

Jon

If my wife got in the Q when it was in the garage unlocked (and I had last locked and unlocked it) and drove to work where she locked it - wouldn't she then have my settings???? And then I would end up replacing my settings with hers which are really mine.

And yes maybe she did. Then again maybe she reset stuff as she was going.
I am not 100% on how it works or how to effect changes. But I am certain if she unlocks it I need to re-unlock it to get my settings.