Is that mesh open enough in the lower opening in particular? I can't tell from the photo the driver's side intake looks like it might be ok but can't tell just looking at this pic I have seen people overheat their cars trying to keep junk out of the radiators with screen that doesn't have enough void space. It starts to have a big impact on flow because you get turbulent air past the mesh, fine mesh really slows down and disturbs airflow. Swing a tennis racquet with the mesh you are using on it, if you feel more resistance with the mesh than wtihout, it's probably too fine to put in front of the main rad (you do have a tennis racquet with you, right? BMW owners usually do?
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