i hope you didnt sign an arbitration agreement. Because if you did you cant take them to court. It will cost you 3500 in arbitration fees alone if you did sign that agreement.
Any repair over 2K the dealer has to get mazda regional involved. The regional rep has to ok the work if it is over 2K worth. Beleive me, if the regional rep sees mods on your car, or talks to the service manager and he tells him that you had mods on, you are SOL.
Could be mazdas fault, but you went against the rules. You modded and they can **** you no matter what.
If you signed an arbitration agreement, you might as well give up now. Save the money for the lawyer etc and just build your motor.
-B