Jason had contacted me yesterday concerning cooling exhaust vents that we placed in the Contra Allure prototype. I have included a few pictures to show the placement of the vents on the bottom of the aircraft. Keep in mind, the Contra prototype has a removable chin cowl where the production Contra Allure does not. This may affect where you decide to place the vents. The most important thing is that your "exhaust" volume is twice that of your "intake". This creates a good airflow. Although I haven't seen a real-life production model yet, I've seen a few pictures and Jason told me that the holes were already there in the cheek cowls for exhaust. The attached pictures are simply of the bottom from the nose looking back. Please excuse the mess on the work table