XM Sat radio Antenna

I have installed my XM sat Radio antenna on the dash just under the plastic cover at the defroster vent and it loses signal. I am thinking of installing on the roof and using the regular antenna mount hole (with a small cut to run wire) to run the XM Sat antenna out unter the regular antenna base so if this doesn't work ideally the regualr antenna mount will cover the small hole cut. They say not to install XM Sat antenna near other antenna. The antenna connector would require a half inch hole to get it through. Has anyone tried this or knows if the regualr antenna will interfere with the XM Sat antenna reception if I do this. If I mount it there higher up on the roof it will be at the same elevation as the tip of the antenna. If I mount it below which is just above the windsheild 3 inches or so will it be less likely to be affected by the regualr antenna? I live in London, Ontario, Canada so reception is reasonable here but not good enough to keep XM sat antenna on the dash.

I live nearby (Detroit) and found that by sliding the antenna up and centered just forward of the center compartment it works just fine. Have you played around with different placement on the dash?
I'd be hesitant to start the project, even with the merger there's plenty of talk of Sirius/XM not making it without a huge but unlikely cash infusion.
Cell phone streaming audio will probably kill satallite soon.

MARCH, do a search here. This subject came up before, if I remember the antenna was installed some place in the windshield wiper aria. My 2c

Something i've noticed on mine, when i place a compass on the dash in several places, it reacts to things inside the dash. One of those places is right above the front edge of the compartment on top center. Seems there's a center speaker in there, with a magnet strong enough to affect a compass. Wouldn't that affect your antennae? Try removing that speaker completely, it isn't necessary for the sound anyway.

Just a thought.

Jef

Mounted on the roof on the left side at the front of the roof rail. 3 bars in any direction of travel. Minor signal losses in deep valleys (like the W.Va turnpike). No trouble under bridges.

I mounted my XM Radio magnet mount antenna just below the AM/FM antenna and routed the small antenna wire along the top edge of the windshield, down the left side of the windshield, into the engine compartment and through an existing grommet hole in the firewall below the steering column. A little black silicone dabbed every few inches of wire around the widshield secures the wire and you can't even see the wiring. And it works great! Same installation on both a 2006 and a 2008 Sprinter.