Pictures of dampers, please.
If you (somehow) have MR dampers, that was a huge misbuild.
If you take out the carpet floor of your trunk (where your spare normally goes), the module for MR is just behind the right rear wheel well. It is a black module box, mounted on a black bracket, which...
Your car should already have brake ducts, but double-check as I cannot remember off the top of my head if they are on all trim levels...
This was the best picture I could find, note the black plastic tube going to the wheel well from the front fascia just above the front underbody shield.
Because I'm curious, have you played with the drive modes on your Shelby yet? Stability control thresholds are opened up a LOT in Sport and Track modes, the system is intrusive in normal mode because it assumes you aren't trying to do anything crazy.
Also, the steering is selectable effort...