I had reception issues and had the dealer replace the inside antenna with an ugly outside one (under warranty) and the reception has improved considerably. However, when the weather breaks I'm going to install the Vaistech adapter to use the shark fin antenna instead (on my dime, of course, since Lexus doesn't support Vaistech).

It almost seems like this Sirius tuner was an afterthought to Lexus. Even installation is considerably more difficult than the XM unit. The inside antenna is a joke, especially if you live in an area with few repeater transmitters. I'm surprised that Lexus has not gotten more complaints.