It does have one on the rear view mirror...there are 3 programable. the way to program it should be in your owners manual. i really suggest checking it out there is some helpful info there.
thanks for the reply. I actually do not have the owner's manual as I bought the car recently used and it didn't come with it. I am going to try to fetch a copy and figure out how to program. Does Lexus have the owner's manual online?