This is non-cruiser related but I am trying to help a friend out.. They have a 2003 Toyota Matrix and while in drive waiting at lights they feel a vibration from the motor, it was suggested they replace the motor mounts (1000$). She asked me if I felt that this was necessary for the longevity of the motor and if that vibration would be causing damage. If the motor mounts aren't broken and its a annoyance I'd say no.. Just wanted to get a few other opinions..!