Hey [MENTION=1848]mishimoto[/MENTION]! I think what I'm going to ask about is out of your wheelhouse, but since you have so many race/performance related items in play, I figured maybe you'd think about it.
There are a bunch of cosmetic splitters commercially available for the Fiesta ST, but really nothing that provides meaningful downforce on the nose.
I'd really like to see someone who knows what they're doing create a splitter with an integrated tray that goes back maybe a foot of so, with securement on the bottom of the radiator support. I'd want to keep that stock air dam/deflector, but something that helps cars with a little added HP/TQ keep their noses flat (preventing a lift) at the end of along straight going to braking would be awesome. Couple that with something like the R5 wing and voila, you have a much more stable flying brick. I would not want to add a wing to this car without a bonafide splitter. Just a thought. The car does not need massive downforce front or back, but adding stability at speed is always handy.