By auto locking, do you mean when walking away from the car, or whilst driving?
We want it to auto-lock when walking away from the car, as our other car (well, the boring one does, the Elise doesn't even have central locking...) does this, and it means we occasionally forget to lock the Yaris as we are so used to the other car locking when we walk away with the key. Any ideas if this is possible?