Has any body else noticed in the mazda5 that you get alot of road noise in the back. Anything to do to dampen it, thinking of installing dynamat cause there is no insulation between the body panels and interior panels. Has anybody done this and is it hard to do.

Yes, the mazda5 is indeed a noisy car on rough roads.
I think this is related to the low profile tires + station wagon design.

But... honestly, i think this is my only real complain about the car... everything else is very good.....