I'm looking forward to your reply, but I want to be clear that I never did say that it is impossible to improve downforce without increasing drag. I assume your solution to do so is by improving the lift-to-drag ratio of the car as a whole using flat undertrays, naca ducts, etc.

I was speaking strictly from the standpoint of a fixed lift to drag ratio. Even formula 1 and LMP1 teams know that in the end they hit a limit where ultimately they must trade downforce for drag. This is what creates "high downforce" and "low drag" configurations for different tracks conditions.

Now, the Crossfire's aerodynamics could be dramatically improved upon given enough money and motivation, reducing drag as well as improving downforce. But I interpreted the original poster's question as one regarding the little flip-up spoiler on our Crossfires, which is to downforce what micro-mini bikinis are for beachwear - they do the job they were designed for!