On the Fabia elegance with maxi dot, does anyone know if you can activate the auto locking yourself or does it have to be done by the dealer?

I think its something the dealer does or if you have vag com software or know someone who does you can do it without taking it in.

Easy with VCDS.  I've done it loads of times.

 

Not sure if maxidot can do it - no experience myself.

Can only be done via VCDS, your local dealer should be able to do it for free or a friendly local Briskodian with VagCom should be able to do it for you.