I have been looking for an exhaust, trying to go for model 16851 from magnaflow. However, i noticed it's only for the megacab and I have a qc. So I called magnaflow and they said they don't make an exhaust for my year and model and that it would void the warranty if I modded an exhaust from them. What gives here? What part number can I use? I don't want to dump before the rear wheel either.