Anybody know where the lower end of this attaches, if anywhere?

Hard to figure the function of it. The main chute goes out to the front to pull in cooler air. Why would there be a need for air behind the radiator?

 

Onto exhaust manifold......draws warm air into engine when cold....Old idea on older vehicles.

 

yup..."preheater duct" I believe was the fancy term

 

Ah yes, I figured it must be something like that. I saw there was some sort of valve guarding the opening. I put in a new radiator and had to remove the intake chute. I found the flange on the manifold where it attaches. I had already reinstalled the air filter, housing, etc. thinking I could install the flexy duct thing later. I tried just now, proved difficult, and I didn't want to take it all apart again, too lazy for that. Then it hit me: I live in a Mediterranean type clime: the bucolic Bay Area. I left it off. I'll save it (yeah right) in case I move to Minnesota. I'll check to see that the valve works, that no air passes. Might even cap it. Hard to imagine it doing any good unless it's subfreezing or near zero.