More permanent grill block
 

made a more permanent partial grill block, the prototype i had on initially was making my car get a bit too hot, so the new one is in 2 pieces with a gap in the middle for extra airflow. It's also attached with more than just zip ties, I put screws into the bottom part of the plastic bumper. If i were to remove them the wholes would be nearly impossible to see unless you got really close. I painted the coroplast black to make it look better, and am quite pleased with my results :) Post pics and data soon.