I have a kenwood unit that plugs into the aux input on the console. I have the antennae literally resting behind the headrest of the rear passenger side seat. Not mounted to anything. I have no reception interference.

Hey i didn't even think of that. Instead of using the tape deck just getting a direct line from the xm to the aux port. Thanks.

Basically your antenna place is the reverse of what mine was in my Expedition. However you just have the magnetic mount in the back correct? I believe the OP has a glass mounted antenna. I believe his main problem has to do with the application on the window, I believe it's supposed to be tint.

That's correct. On my OEM system, the spec calls for the dealer to mount the antenna on the glass, in the shade/dot pattern behind the rear view mirror (or so I'm told). I'm reasonably confident that such placement, in combination with the OEM antenna, has left me with the poor reception I'm complaining about.

The dealer now proposes to hook an antenna originally designed for a 2005 Land Cruiser into my Sirius receiver, and mount that somewhere on the exterior like the roof or trunk lid. Hopefully I'll be able to post tomorrow night that this solution worked.

I went to BEst Buy and bought external antenna and put it on back center of roof (where you see them on most factory cars) and it made a big improvement, although Sirius always gave me some drop outs where XM was also solid.

Out of curiosity, what kind of tuner was the antenna plugging into?

Just to close the loop on this, and to help out any future owners with similar Sirius reception issues, my problem is now resolved.

The dealer installed an external antenna on my 2007 Camry Hybrid. The antenna was originally designed for a 2005 Land Cruiser. It fit the receiver that came with the OEM Sirius Fit Kit that the dealer installed prior to my taking delivery. Toyota's instructions call for the dealer to place the antenna on the inside of the windshield, behind the rear view mirror, in the shade/pattern of dots. That placement was undoubtedly the cause of my frequent, unexplained drop outs in reception.

Now that the external antenna is connected, the reception problems are 99% gone. Last night and this morning I drove the same areas in which I'd been having problems, and there were almost no drop outs. The drop outs I did experience were shorter and less noticeable, and within my personal level of acceptability.

Bottom line: the internal antenna, at least when placed in the sunshade area of the windshield, presents unacceptable difficulty with reception. The fix for me was an external antenna.

Cosmetically, I'm not completely satisfied. The dealer put the antenna on the trunk lid, which is fine (if you want good reception, it has to go outside somewhere!), but it isn't centered. They stuck it off to the passenger side of the trunk. It might be that they didn't have enough cable to put it in the center, but I don't love the way it looks. Also, the dealer left the offending interior antenna right where it was installed. Common sense would have dictated removing it, in my view, but I guess I can live with it. If the dealer was closer to home, I'd have them fix it.

Thanks to everyone who chimed in with their comments in this thread.