My seats and mirrors would always move to a different position whenever I would unlock the car.
Frustrated I started searching on all forums for the solution.
Interestingly enough I couldn't find a definitive answer (at least the searches I did).
There was a suggestion to set seat and mirror positions to my liking then
1. insert key in ignition
2. turn ignition on
3. pull parking brake (not sure if this has anything to do with it but doesn't hurt)
3. press the M on the seat memory controls
4. press the unlock button on your key both at the same time and hold for a few seconds.
This worked for me. Just wanted to share.
Interestingly, my seat memory panel does not have a "key" button.
Only "M" and 1, 2, 3 buttons.
Hope this helps.