My LS460 will chirp at a stop as the brake apply pressure is reduced and reapplied. It's not at the point that there is any vehicle movement, so it's not coming from any rotor/pad issue. Also, it seems to be coming from under the hood/behind the firewall. I can't delete this post so doing an edit. It seems like this is coming from the brake actuator as there is a TSB for it. L-SB-0047-19