Does anyone know where you can buy this metal piece? Or do you have to make it out of sheet metal

 

Signal Auto makes these.

 

That is my car, and i made it out of sheet metal. It is very easy, just mock one up with cardboard first... my radiator is set up vertically and the cover is acting as a radiator shroud forcing air through the radiator, here are some more pics:

 

There is a Carbing one for sale on Ebay.

 

The Carbing one looks nothing like that.

 

the one you made looks good!