You found a condom in your front bumper???? Geez, where do you drive your boxster anyway, through whorehouses?
The mesh grills seem to impede airflow to me. I just take my home vacuum cleaner's crevice tool and duct tape it to my shop vac (more power) and clean out both of them from time to time.
Then I shoot a stream of water through the radiators to clean the dirt and dust out of them.