The rear window defrost lines reflects the lights of a car behind you. If there is one car behind you there is 20 lines of lights showing, if there is 2 cars behind you you now have 40 lines of lights be showing in your rear window and if three cars 60 lines and etc. It casuses a very bad distraction and you can not see anything else through your rear window. So I can not see anything clearly thorugh my rear window at night. During the day it is there but not as bright. If feel this is a safety hazard and Toyota should fix the problem.