technobabbler
M3LR MSM No FSD
It's worth noting that I also have an older M3 with radar, but since I have FSD beta the car is no longer using it, so I've had the chance to see the exact same car with/without radar. And, I've seen almost no phantom braking with OR without radar .. certainly never the "slam on the brakes" others have reported. So it's not as simple as radar vs non-radar.
I can't speak to anything FSD related as I don't have it and I truly don't know what the difference is under the hood so to speak.