I'm pretty sure that I hear the doors lock themselves when I start driving. I got a GTS with fast key. Maybe I'm on crack , but I swear it does it lol.

 

I always hear a little door click, but it's never the doors actually locking.

(GTS, CVT, S&S package)

 

If you have FAST key what I posted works everytime for me.

You need to lock the doors with the power lock switch in the vehicle BEFORE starting the engine for them to remain locked after exiting and closing the door.