They all lock automatically if you unlock them but don't open the door. But to lock as you walk away? Sounds fraught with disaster to me. I remember when I had a Verso or something with keyless ignition. You could start it, drive the missus to town, get out with the keys in your pocket and let her drive off to the shoe shop. Of course she stalls at the lights and .... no keys! Imagine the scenarios of it locking itself. Plus of course the electronics it would need not to do that under the wrong circumstances. I'd turn it off it it came on a vehicle I owned I should think.