My experience with catalytic converters is only one of my vw's actually
had the dense honeycomb inside the can.
I think that only California equipped cars received the contents, the
rest had a hollow can.
I say this because my 90 California docked GL was the only one.
My 89 wolfsburg was hollow, my purchased new 87 jetta GLI was hollow, as
well as all my other  5 OHC VW's.
I don't think this is a topic that VWoA will admit too, and if you order
a new one it will have the honeycomb in it.
I think that VW new that they were running well under the EPA guidelines
for the rest of the country.
So the majority of the country has a fake catt. Cost factor?
If you look closely into the can as a friend of mine and me have you
will find there is no evidence of there ever containing the honeycomb,
like some kind of weld slag or pieces of a bracket.

I recently switched the exhaust from the (so called) catt back on my 90
(with catt) with the one from the
89 (fake catt). The hp difference was slightly better, the sound from
the exhaust was much different and slightly louder.

Rob