Are there cars or concept cars with variable radiator grill openings?
 

Where you can set it to partially closed at highway speeds to minimize drag, yet fully open at lower speeds for better cooling?

I've read its used on some airplanes and I was wondering if it has been tried in cars.

Ford Focus, I think 2012 and later has grille shutters that are controlled by the radiator exit coolant temperature.

regards
Mech

Actually, if I remember correctly, a few companies have been doing this for their mid level, "eco" oriented vehicles. I want to say Ford (Fiesta?, Focus) and Chevy (Cruze?). I just remember a year or so ago thinking "Heck Yea!" and then later thinking "okay, now everyone is doing it" lol

I look forward to the day when all vehicles come standard with it, and we can just close them (then pop the fuse) and fully seal it nicely- or close it all but that moving opening.

yes, there are.
In fact one is advetised on tv on it's 2013 model....for the life of me I cant remember the model

BMW has been using shutter-style radiator blocks in some of their diesels for years now.