Here are the photos of my front "SnowPlow" areo device. While it is not fancy and does not look very aerodynamic, it certainly does the job and counters the lift caused bu my clam shells. My front end is now quite stable at any speed and dives into turns.
I would like to add more downforce at the rear. I think a wing and the Fluke diffuser could add a more grip on exit and a few more mph at the top end at VIR.