Hello all! I was not sure were to post this, but I was asked a very interesting thought experiment on Facebook today and was wondering if I could get everyone's opinions on it. Ok, so suppose we could really annoy Einstein and manage to get a car to go the speed of light. The question is, would the stereo speaker's work? Now I have two different theories. One, assuming the system within the cabin is unchanging, then the principals of reference frames would dictate that the speakers would work fine relative to you. But all of the particles in the car are going faster than the speed of light, so if a sound wave was emitted, would you not move faster than it could propagate? And if that happens, would you be able to hear anything at all? Just thought I'd share this little bit of intrigue with you all.