It is not that e=mc2 is wrong. It is the interpretation that since nothing can be “accelerated” past the speed of light that nothing can go faster than the speed of light. Velocity and Acceleration are being confused. Einstein was right to say nothing can be accelerated from rest to faster than 299,792,458 metres in “one” second. The wrong interpretation is to say nothing can have a velocity greater than c. By adding the speed limit we are in effect creating a central rest frame of reference to the universe. And from what I have read I thought that was what Einstein was trying to disprove. With the Lorentz Transformation(LT) we are dealing with only two reference frames. One is at rest. And it deals with a delta of time. If additional LT frames were actually linked together the limit of the acceleration would still hold true between frames. But the velocity is not what is being looked at it is the delta or the acceleration. So my thought experiment would be shooting a rail gun into space. That in turn shoots another rail gun that in turns shots another… Nothing is going to stop the final projectile from exceeding the velocity of light as it relates to its speed moving away from the original frame of reference.