Good to see this is going full steam ahead
From the top of my head here are a couple of things that spring to mind:
- Encrypted keys?
- Location pin-pointing (although from what I have read on the net this is not really feasible easily without having many 'base-stations' spread around the house)
- The automatic part in the keyfob is more important than having buttons on it? So maybe also a key without extra buttons.
- Reliable signal strenght read-out for events based on how close the key is to the 'base-station'.
-Works in cars
-A key that can be powered by the car's power maybe, aka 12V?
-Keys should be small enough to be pocketable