My understanding is that the sim card is non-removable. I suppose if someone wanted to go through all the trouble, one could devise an adapter that contains wires and pins that get connected to the hard-wired sim, and goes to a circuit board that is then plugged into a phone to read the phone number.
I'm not sure it's non-removable--other than that it's not supposed to be removed by the owner. It is located in a very hard to get at area. (I think you have to remove the dash and display to get at it.)