Thanks, the dynamat is in and the speaker and power wires have been run on separate sides of the car. I'll keep in mind the interconnects.

I'll have to wait to see if the dynamat really made a difference as the car's eviscerated on jack stands right now. You may very well be right on the inability to tell difference between a higher end and mid range amp in the Mustang. The guys over at the mustang forum have seen very mixed results on reducing the noise in these cars.