Hi i made sucesfully a spare key, just sharing

Hi guys, i live in Mexico and i was able to make successfully a spare key, After doing some research i found that bmw key , has some attributes that allowed me to reprogram it The key is working ok, open/close and start the engine. With a little help of an electronic engineer now im really happy
Maybe this info is important for somebody. My rangie is 1996 4.0 .

Best regards
From Mexico