Well I have been experiencing some problems with the speed. On startup there is a rattle coming from underneath the head "so says Mazda" and my rear diff. feels like it is coming undone (you can feel it moving occasionally) Anyways I took it into Mazda today and they take it back for a couple min. and then tell me they will not look at either of the problems because I have an exhaust intake and bov. I stated that it is the buyers right to modify their car and the warranty cannot be voided unless the problem is directly caused by the aftermarket part. He goes on to say that the "extreme" power increase is what could cause the rear diff to go out, and the rattle could also be caused by the power increase. They said that they will not even look at the problem to see if it was caused by the modifications and they said the only way they will work on it is if I can put the car back to stock (which i cant because i cut the bolts to the catback off) and bring it in. If anyone knows anything that could help me resolve this matter that would be greattttt. (Im waiting for a call back from some district man who is in charge of the warranties so I will post what he says)