Mounted the Safety Trim Boost unit on the rack. The other unit that I want to mount on this rack is the IFF. The piece of plywood is cut out to the same footprint as the GTX-45R that I am installing. The antenna for the IFF is farther forward, just behind the passenger seat so it is not close to the autopilot servos. I am looking into other's experiences as to possible interference with the autopilot from the IFF unit itself before I actually mount it.