Rear Windsheild Defogger

[LEXUS IS250 AWD]

With the colder weather now here I happen to notice that when I hit the rear defogger button most of the rear windshield clears up except for the top 2-3 lines. I brought this to my local dealer's attention and they advised that the top few lines are the imbedded radio antenna and they are not meant to defog the windshield. But he didn't seem too sure so I called another dealer and as usual he told me to bring the car in so they can take a look at it. Anyone know for sure?

[retired00]

If you look closely, you'll see the top grid is separated from the rest. It's the antenna.

[reyoasian]

Same thing with me man, I think your dealer's right.