Nate, thanks for the "woven felt" -- now I have a term to search for (!), last time after I saw the car I ordered simply black felt...M!ke looked at this with me, and yes, the same stuff is used there on the glovebox and the entire surface in the front trunk. It is thin (I remember less than 2mm) and yes, it is woven.
Good eye on the bitumen over the radiator, it is 6mm--I'll probably end up with closed cell polypropylene foam there...Lee