This is an interesting topic that has been raised in the past. What you should first understand is that it is a highly subjective system that varies from tuner to tuner and within the automotive system. For example: Brake kits from one tuner may be labeled one type and then be labeled a completely different type by another tuner. Furthermore, a Stage 2 brake kit has no relation to the Stage 2 engine upgrade - even owners argue what makes a stage 2 vs stage 2.5 vs stage 3. It's comical sometimes to read the claims. Try not to get caught up in the "Stage" hype. In fact, it's more important to be tuning (upgrading) your car with the components that fit your needs/desires.