From my blog: http://mymicra.com/?p=367
My theory works like this: The gaps in the grille are large enough to allow a large stone to pass through from the truck you’re following, and that stone becomes embedded in the condenser coil. Eventually, the coil leaks, and the air conditioning stops working. If it happens in the wintertime, you may be unaware that you’ve lost the refrigerant which also acts as a lubricant for your compressor, and next summer, it’s time to replace the coil, seals, and compressor.
The mesh is gutter guard, cut roughly to the size and shape of the grille, then held in place with small black zip ties. From a distance, it’s nearly impossible to tell it’s there. I had this on my previous car, and the air conditioning never failed once in the 12 years it was in service.
Thoughts?