Can you work from a positive?
What is the technique you use? This part would be 3-D, plus have hollow sections which will be ducts. Right now I only have doodle/drawings and am thinking I need to make part to work out details. Thoughts?
The more I look at the drawings, I am thinking this is 2 pieces. One is an air dam with brake ducts, ducts going back to form the under cover and longitudinal fins. A second part which would be the splitter and canards which would slide on the front of the dam for track use, maybe just an engagement lip and a couple of pins holding it on.