I agree with most post here, brakes are consider a wear and tear item. Warranties on them is hit or miss, some dealer will do and some wont. The dealer doesnt know how you use your brake and how much abuse your brake takes. Instead of dumping your car, you can buy a whole new set of after market brakes and rotors for $500 and have a shop put it in. The rattles on your dash, door and pillars are a difference story :) Those are harder to fix.
Do you still get the brake malfunction message on your dash, if you do, then you have a good case for the lemon law.
I do agree agree with you though, Lexus does not make cars like they use to.