I just installed an Antenna Specialists XM20/CP antenna in my Coupe. I installed it under the 3ed brake lite housing on the rear deck. It fits fine. No holes to drill either. To access the housing, simply lift the housing and pull toward front of the car. Slip the XM antenna in, and run the wires through the hole forward of the trunk light. You will likely have to remove some of the padding in the brake light housing. Then re-install. Works fine, and no ugly antenna to see anywhere. Anyone can install this antenna.
http://www.sdarsantennas.com/prod_552.php

BillR

 

Bill: Thanks for the very interesting post. Really would appreciate a follow up report perhaps several weeks later concerning your experience with dropouts. I just installed the Infiniti SAT/XM system in my G35c, and purchased the TERK antenna. I considered using the location you suggest, but decided against it because of the two layers of wires in the back window. One is for the defroster, the second is the diversity antenna for the AM/FM radios. I thought they would interfere with signal reception. Perhaps not.
We have lots of hills and heavy tree cover in our area of Marin County CA, both of which cause reception problems for all types of radio receivers. In a recent rally of G35 drivers, I found almost no dropouts while going through heavy tree cover and many hills. This was with the trunk mounted TERK antenna. Please keep us updated on your internal antenna Bill.

803G35c/C_Blue/Willow/6AT/Premium/Splash/Garmin SteetPilot III/V1/SAT/XM

 

Bill: Tonight I went to the Antenna Specialists web site to look up the antenna you suggested (XM20/CP). For their installation instructions in number 1. they say: "Assure 6 inch minimum metallic ground plane surface surrounds the antenna." Did you insert a metal plate under the rear break light housing to provide a ground plane for the antenna? Or was some other means used to establish the required ground plane?

03G35c/C_Blue/Willow/5AT/Premium/Splash/Garmin SteetPilot III/V1/SAT/XM

 

No,
It works fine. Just put it under there, no need to even mount (stick) it to anything. Absolutly nothing visible and works 100%.
If it makes you feel better, underneath the parcel shelf is a metal "parcel shelf" for a ground plane.


BillR

 

Bill: Thanks for the reply. Was wondering if there was any metal in that area. That certainly would work for any ground plane requirement. Wonder why dropouts vary so much. Today, while driving around town, I was getting lots (20) dropouts with the antenna currently mounted on the trunk lid approximately six inches from the rear glass. On other days, there would be only one or two dropouts. ????

03G35c/C_Blue/Willow/5AT/Premium/Splash/Garmin SteetPilot III/V1/SAT/XM

 

Bill: Thanks to your posts, I was able to accomplish the stealth XM antenna install with a TERK XM3 antenna. Had a devil of a time releasing the cyclops brake lite housing until I figured out that there are two release catches that have to be pushed toward the back of the car before you can lift the housing up. Since the TERK is a mag mount, I placed a small plate of metal under it and some foam rubber on the top before putting everything back together. Nothing can be seen now.
However, I am getting more dropouts than when the antenna was mounted on the trunk lid.

03G35c/C_Blue/Willow/5AT/Premium/Splash/Garmin SteetPilot III/V1/SAT/XM

60972-G35c At GGNRA Thumb.jpg