I can't believe people allow install kids to drill a bunch of holes in thier grills for mounting snap fastners on those winter fronts. It looks just hideous in the summer. I run cardboard in front of my rad every winter and find covering about 1/3 works best in my climate. I flatten out a cardboard box and jam it up in between the condenser and the rad. If I want it to run hotter or cooler I just change the size of the box.
Curt B.