Same here dan-o. I built the car running the turnbuckles in and out of the ball cups several times. I did have to take two of the links back off and run them in and out again a few times. Those two were popping off when adjusting camber. But all good now.
Haven't had one pop off yet from a crash. Knock on wood. Probably at least 20 battery packs worth of run time now.
I actually notice the turnbuckles move in/out slightly, but only from rubbing the pipe at full speed or during crashes. But I have the same thing happen in 8th scale sometimes. Just gotta check camber and toe before/after each run.
Hand up. I've always used RPM ballcups on the Associated cars.