I finally did something. I got sick of the cold mornings, and the 10 minutes till the cabin is partially warm. Found some old cardboard boxes, cut them up, and covered most of the grill/bumper openings. It's not pretty, I didn't paint them, I didn't even try to make the cuts straight or even. I just wanted to see how it would affect the warm up times.
You can easily see the white cardboard behind the upper grills, and the brown behind the lower.
See the simple screws? the lopsided mount? There are vents on the horizontal plane. This car has too much cooling.
It's functional, and ugly. If it works, I'll clean it up with plastic molded to the bumper, which I'll have to take off. Not an easy car to work on. I left one open, because it's a pain to get the cardboard to stay.
Just filled the tank, I'll drive the same (lots of throttle when I'm bored) and in 330 miles/3 weeks we'll see if it made a sizeable difference in warmup and mileage.