Its not just wives. I've had neighbors call me to say they are overheating - what can they do? Call because of similar tractors. Some of these have had lots of tractor experience. I describe the screens and sure enough they call back and tell me they are plugged. I believe this is more common today because companies are using more fins per inch in their radiators, oil coolers, air conditioner condensers, and inter coolers so trash that would have flowed through in the past is now trapped. In addition there are often 4 cores whereas in the past with a gear transmission, open platform, and no turbo, there was only one. Another way to improve cooling is to stagger the tubes instead of making them inline. Staggered tubes gives a considerable cooling boost but also results in quicker plugging. Manufacturers have compensated by placing the screens in front to make it easier to clean, but in any condition that kicks up pieces of plants plugging is going to be a problem. In combines where the machine is always working in a cloud of chaff, we could not have more than 4.5 fins per inch. I have measured tractors with 8 to 11 fins per inch. Lots more surface area to dissipate heat but very prone to plugging.