I was getting very spotty reception from my factory XM antenna on the rear speaker shelf, close to the bottom of the glass. Placing it outside the car I got great reception. My windows have 30% Solargard black tint. I tried an XM Roady2 with it's antenna and got the same results. I placed the miniscule magnetic Roady2 antenna on the metal speaker grille on the right side of the front dash and got full strength signal, even in my garage. Food for thought

 

The metallic layer in tint will do that! Good advice!

 

The factory install setup no longer uses an external antenna but rather an internal one placed right next to the rear view mirror on the passenger side.

 

The Sirius Satelite kit does, but I wasn't aware the XM kit had the same antenna. Are you sure?

 

I have Sirius but maybe the XM is different.

 

I had Sirius installed in my 2006 GS300 about a month ago. Declined XM in May when I bought my GS and waited for Sirius. I have the Sirius antenna installed inside at the top of the winshield just right of the rear view mirror. I noticed the antenna initially after being installed but now don'e even notice it. My reception has been great. Only a few times have I lost reception for just a couple seconds when going under a very wide bridge overpass. I even get reception in my garage. I like the 3 Sirius satelitte choices so I keep one setting on music, one on news and one on talk radio. Only complaint is that the artist name and song do not always spell out completely. Had FM Sirius in my RX330 and the reception was no where near as good as this integrated unit. I really enjoy my satellite radio

 

Some people have had the XM "block" antenna installed when they got the Sirius receiver, so apparently they must be interchangable. I've had both Siurius and XM and I found the reception to be pretty much the same. Antenna placement is more critical to good reception rather than XM vs. Sirius.