Firewall questions

[Calan]

Couple of questions (see pic below):

A). What is this plastic piece (and the similar one on the drivers side) for?

B). I was looking for a cover plate for the A/C evaporator (another thread), but I'll probably just make one.

C). What is this bolt for? Does it hold the heater core in? It sits right under the cruise control box, and has nothing attached to it on the firewall side.

You must be logged in to view this image or video.

 

[92AWDHX40]

That bolt not sure, there are 3 that hold the cruise control box.

 

[HIGHPSI4]

A is a dust shield/grease stop. B, make temp plug with silicon. C just an extra bolt in the fire wall. A lot of 1991's I have seen had this unused bolt. A discussion for C was had here: 1G What is this bolt for?.