That doesn't sound good. The air filter is ahead of the resonator, and is located in the driver-side wheel well (above the skirting material). So what you are seeing in your resonator is an indication of what has been going through your engine. You need to find where the air leak is, between the filter and the resonator, or what is wrong with the filter unit.I think I figured it out. The dust is just that. Road dirt. I think there is nothing inside. At first i thought it might have once been scotch bright or something like that.