Talking in generalities here. I've bought keys cut for my car from the dealers, sight unseen. So that means they have a way of knowing what code the EWS system is looking for from the key in the ignition (not talking keyless entry here) AND they have a way to write that to a blank key (since they never touched my car, they can't have added to its list). So, they should be able to write that code to your two old keys. I suspect BMW NA actually cuts and programs the keys, so the only way for the dealer to discover your cars secret code is to read it out of a working key... Still don't know how..,

I have read and written those codes from the cars memory on an early R53 (MINI) using DIS, but on that car, you actually go into the cars memory and program each new key. It's clearly different than the E53.

__________________
David.X5
2001 X5 4.4i Sport
SOLD! at 160k miles