Rumor has it Tesla will be creating the ability to warn pedestrians, since the car is so quiet. Apparently this will be for cars with "external;" speakers. I just walked around my T-3 and didn't see any speakers. I don't know whether to go to Best Buy and get some or not. What are "external" speakers? How do I find out whether or not I have them? The only external speakers I have now are my hearing aids.