Here are some pictures of the shutter on the right side of the air dam in front of the radiator. This is the best design so I will show details of it only.
I started by using a hack saw blade to remove all of the vertical dividers in the grill opening. This leaves a hole that is 5" by 23". The right shutter is 5" tall by 10" long. It is made from .090" aluminum sheet that was in the scrap pile at work.
In this picture we will be only looking at the shutter on the left. It shows the shutter in the open position. Note the cable pull at the top which is out the full 2" of its throw.
Here is a shot from the back
The frame of the shutter is held together with 6/32 button head bolts and nylock nuts. Each corner is reinforced with a 1"X1" by 5" 90 degree angle.
Note that the "hinges" are made from 1/4" round aluminum rod that is flattened on the end where it is attached to the shutter. The holes in the frame for the round part of the hinge are "oversized" to allow for slack so the hinge doses not bind when being opened and closed. This is because these cheap cables twist as they are opened and closed and will bind up the shutters if they are too tight. The shutters are also about 1/8" shorter than the opening on each side to allow them to move sideways when the cable twists.
Also note that the shutters are curved on their leading edge to make them stiffer.
More pictures
