The RD inner wheelhouse repair piece has a second layer on the inside. I've seen
rust repair progress pics that seem to show that circular hole which is cut in the
inside layer, presumably on the original factory piece if they're just starting the repair.
Click to view attachment
Question is:
* Is the second layer only in the aftermarket repair piece?
* Was the second layer always used by factory?
* or Was the second layer used only in certain years or a running change?

This is not to be confused with the inner long engine compartment which we
know has an outer smooth layer and an inner corrugated layer.


Thanks

The original factory piece is double walled like the RD replacement piece. AFAIK, that is true for all model years. There are some other aftermarket replacements for that area that look different from the original. I wonder if that is what you have seen. Other than a few minor wrinkles from the pressing on the RD piece, it was a perfect match for the original when I did mine.

I have a very early car, and found that there is only a single layer:

Click to view attachment