The problem(s) I had with the Colgan bra is it's designed for "normal" daily use and it's not track friendly. The Colgan bra that I used for my first "track" car, my old E46 323Ci, ended up scratching my paint badly due to the top half of the bra bouncing around at 120+ mph. The problem is the bra tend to stretch if used regularly and when it's a couple years old, will allow some flex and air to get trapped under the bra.
It could work, if you manage to keep the underside of the bra clean, and then add painter's tape along the edges. But if you're going to go all noob tape on the car, might as well forgo the bra.
p.s.: Be on the look out, if you guys are jonesing for more track action, for the May 3rd Auto Club Speedway announcement to go out this week. I've got a couple more administrative stuff to take care of on the back end.