I am the second owner of this car and I have always wondered why the XM reception was poor (blocked by trees, etc). Today it finally got to me so I looked for the XM unit and found it velcro-taped to the passenger side fender in the trunk. This box has a Pioneer GEX-M8087XM and Toyota parts sticker so it was likely dealer installed. Seems the wire was spliced and poorly taped back together at some point in the car's past. (see the picture circled in blue) With a shielded cable carrying such a low signal, this is not the right way to run a wire. I ordered a new antenna from Amazon for $20 today and in a few days it will be replaced. Hopefully my reception will be better.

 

I have a 2005 with XM (or sirrius) dealer installed and I get the same reception issues. Where is your antenna mounted? Mine is on the trunk

 

I'm all ears here

 

center of the trunk lid, front edge for my XM black square pad,,

yes heavy stands of trees will block the signal, so do long overpasses,,

Derry

 

Mine was inside the rear window when I got the car and I had the dealer move it. That is possibly when the splice and repair was made. I wanted it moved to the trunk but they moved it to the roof above the windshield on the passenger side. I had an Avalon with aftermarket XM before this and it used a bigger antenna (TRK-SR2 XM) with the green and yellow wires. One is for the satellite and one is for terrestrial broadcast in major cities. My Avalon got great reception and I also have a Honda with factory XM and it has no dropped signals except for tall buildings and long bridges. In the picture you can see that my LS now uses the 1-2 adapter for the newer single wire antenna which is smaller. I figured I'd try the magnetic mount single wire first which was only $20. If that is no better than the one I have I am going to get another TRK-SR2 since my old Pioneer radio can use it. Most newer radios only have one pink input.
For more technical information, see this report which discusses mounting location at least 6" from the edge of the metal surface it is mounted on:
http://www.mwrf.com/Articles/Print.cfm?ArticleID=5892

 

Whats the box under the blue circle ???

 

The Nav system computer and where you install the Nav DVD.

 

I was very surprised how many electrical boxes are back in that area (at least 5).

 

ok thanks ......

 

Here's the update: I ordered the wrong part online first. It was for the Roadie and had the incorrect connector. I returned it to Amazon for a full refund, minus the 2 bucks return shipping. The correct one (Terk XMICRO2 ) arrived today and after a quick install centered on the trunk forward edge, I drove around the roads that blocked the previous signal. This one is not perfect but is considerably better that the previous antenna with the improper crimp. There is a small stretch of road that used to loose signal 5-6 times and now it is only lost once. So I'll see if I can live with this for a while and look for a deal on the larger TRK-SR2 which seems to be discontinued but available sometimes online.