My 2007 530i has the "keyless" remote--which actually has the hidden key. Last week, with only 339 miles on it, it developed "amnesia" and could not remember either of the keys--or the emergency one in the glove box. We had to call BMW Assist and have it flat bedded back to the dealer, where they took the steering column apart and put in an entirely new key receptacle. They claimed it was only the second time that they have needed to replace the key receptacle. So far, it seems to be operating okay now. I have also seen the new remotes on 300 series as well--a 2007 loaner that we had from the dealership last summer.
Beach Exec Panama City Beach, FL.