I bought an XM Roady yesterday and have been having a ball with it, playing around trying to figure out best mounting, etc. I've learned a few things so thought I'd share (this is my third XM receiver and beginning to learn the ropes, now) The following is a sort of mini-review of the Roady.
1. The Roady is the best buy going - comes with a lot of mounting accessories, right now, they're on sale to include a free wireless FM Modulator.
2. They don't advertise this fact, but the Roady also has line-level (accessory) out that will go into inputs in some car receivers, and, importantly, virtually all home stereo receivers. This means one Roady for 120 bucks does double duty in the house!!
3. There is also a kit for sale on the XM site for 19.95 with a separate indoor antenna (so you don't have to unhook your whole mobile setup) as well as a little wall wart for DC power and the cable to hook to your stereo (what a bargain!)
4. Playing with the standard (tiny) magnetic antenna, it doesn't seem to be too critical where it's located, as long as the SW (from VA) horizon isn't blocked. I have it indoors right now, flush against the top of a TV set and it's playing fine. (My house is wooden, though, don't try that with aluminum siding!) I've ordered the indoor kit and will see how that antenna works, but expect no problems. (Place in a window sill)
5. In the Viper, I have the adhesive pad for the Roady mount affixed just above the ashtray on the vinyl. The instructions include removal procedures, so hope it can be taken off without leaving too much of an adhesive residue whenever. (They seem to indicate this is designed into it). This mounting position lets me use the wireless FM modulator (which is pretty trick, btw) to receive XM (sounds pretty good, too) on my choice of about 6-8 frequencies. Thus there are only two connections to the unit - cigarette plug (which gets power and sends the FM modulated sig to the car) and the antenna. As I said, antenna placement does not seem especially critical as our cars are mostly plastic. I have the tiny antenna right next to the unit behind the gearshift, but the metal is under the vinyl and the mag doesn't grip very well (probably fly off and hit the floor when I brake hard) so I'll look for a better spot. (I should probably also mention the Roady comes with one of those tape cassette feeders for those who still have cassette inputs on their stereos; I don't)
6. Audio quality - Roady is fantastic through the high-end system (listening right now) here in the office. In the Viper, using the FM wireless modulation through the cigarette lighter plug, it seems to be a bit noisier (hiss) but only noticeable when the music is extremely quiet. On the whole, it beats FM broadcast through the factory Alpine and speakers, and is a close second to CD. There is some very faint "motorboating" sound that's more perceptible on the lower channels - suggest setting the modulator frequency in the "107 Mhz range" rather than 87. Seems to be less there. But this is nit-picking - it sounds very good and makes it possible to have XM at bargain-basement prices that's useful indoors as well. (If you're lucky enough to have AUX inputs in your mobile stereo, you're really in luck and will have fantastic CD-quality audio). So one subscription (monthly fee) serves effectively your home, all your vehicles, rental cars for trips, etc., etc.
Best bargain I've found yet. Highly recommended.