Warranty Question

Normally installing an exhaust system does not void your manufacturer warranty, but this is usually dependent on whether or not the installation is a direct replacement or if fabrication/modification is necessary.  I would contact Mina (or the vendor that sold it to you) and collect the appropriate documentation for your argument.  Then take this information to the dealership service department and speak to them in person.  If possible, have them document the answer so that you don't get screwed in the end.

You should never install any product that may void your warranty unless first taking the proper channels to resolve any gray area.  Unless, of course, you don't care if you void your warranty.