>> > How much of a sound deadening/proofing difference
>> does this stuff make?

I put it along the wall behind the fridge/sink/etc and under/behind the
rear bench seat.  Can't tell any difference when driving, but the
difference is pretty obvious if you tap on the panel.  However, this is on
an air cooled vanagon which does not have the seal on the leading edge of
the front doors.  The wind noise at highway speeds is the largest source
of noise at this point.

I also put the stuff inside the doors.  Made no difference while driving,
but made a HUGE difference when shutting the doors.  I still have a bunch
of Fatmat waiting to be installed when I have time.

jake