Audio Systems: lexus xm installation, lexus radio, xm radio

Question
I have an IS 250 and I want to add an xm radio. I am supposed to install a sticky mount to the inside of the rear window on the FM antenna. I'm not sure how to differentiate between the antenna and the defrost.  

Answer
the bottom one is the antenna the large one on top is the heater
if the audio input is not clear this  ipod interface will give you one audio aux input port to the lexus radio

http://www.oemautosound.com/pc-356-159-dice-lexus-to-ipod-kit-text-ready.aspx