New owner - Trunk liner?
 

My recent purchase did not come with any carpet for trunk. It gets pretty warm back there. Did the 914 have an insulated matting for the trunk? If so, can it still be bought? If not, what's a good substitute?

just a simple gray carpet - repro are available on Pelican & other sites

sixes also had a thick foam-rubber pad right over the muffler section

- a piece of DEI mat over the muffler section will help a lot with your concern - available at any parts store

There were a couple of different parts used over the years. There was a rubber mat (Possibly a closed-cell foam? I remember it being a bit heavy) and there was a mat that had a plastic or rubber covering on it. There was also a carpet. I do not remember which type went with any given year, though. I think that the carpet was put down on top of the mat in at least some cases.

If you are simply trying to cut down on the heat getting into the trunk, you can fab up a simple sheet-aluminum heat shield. Make sure it doesn't touch the heat source (exhaust and muffler) or the trunk floor, and it should help at least some. Ducting cool air into the area between the exhaust and trunk floor can also help.

--DD