GXM 30 XM smart antenna delivers XM Satellite Radio, NavTraffic and Weather services to your compatible Garmin. Roughly 3 inches in diameter, the GXM 30 processes all XM information and sends the finished data to your unit for display. The GXM 30 requires a XM Satellite subscription(s). Traffic services are available only in select cities where XM Nav Traffic coverage exists.

User Reviews about Garmin GXM 30 Weather and Audio XM Satellite Receiver (requires subscription)

I originally got this when I had a StreetPilot 2820. I tried the FM Traffic but it didn't seem to be giving me very accurate information at the time (the FM Service seems to have improved since then). Anyway the bottom line for this unit:

- it's about the size and shape of a hockey puck
- it is a specialized XM Radio. That is why it's so expensive (even then it still seems a bit expensive to me). If you get it and subscribe to XM you can plug this unit into any Garmin GPS and it will continue functioning.
- the cable that is attached to it is 2 meters, I believe. Kind of short for most people. You can put two of the Garmin extension cables ($15 on Amazon) between your GPS and the XM Radio so that you can place it just about anywhere on your car. It's limited by the specs of USB cable length.
- you can subscribe to just Traffic (~[...]/month I think), XM + traffic (which I think will run you [...] (XM) + [...](traffic) + [...] (the music royality fee introduced over the summer-2009) = [...]/month, or XM + traffic + weather (weather adds an additional [...] to the traffic but will get you weather radar + other features/maps if your GPS supports it)
- traffic service comes with basic weather which is current conditions and forecast for major cities in the U.S. If your GPS doesn't support the additional weather maps then definitely only subscribe to the traffic service.
- You can get a lifetime subscription which will cover the XM radio portion. Although tough to find on their site (which seems stupid) I believe it's $399 for XM Everything and $499 for XM Everything + Best of Sirius (some of the missing channels from Sirius - at that point you basically have most of what XM Sirius has to offer in terms of programming).
- If you get a lifetime subscription it is for the life of the radio (not you) although you can transfer it up to 3 times for a fee of [...] each time.
- Lifetime subscription does not include traffic or weather. Those will still cost you [...] and [...], respectively, each month.
- The lifetime subscription will end up paying for itself in about 2.5 years.

Reception: for the best reception put the radio (puck) on top of your car (roof better) with about a 6-inch radius of metal (your roof or trunk) around it. I actually have mine mounted under the plastic of my dash and it works well with a trade-off that it has more drop-outs than when it was mounted to the roof. If you're driving in the mountains, regardless of whether it's Sirius or XM, you're going to have occassional dropouts. The mountains themselves will get in the way. Like another reviewer I've driven up into the Great Smoky Mountains and I too have frequent dropouts, even with the antennas on top of the car. Generally speaking, except for those conditions it works quite well.

Traffic: The traffic services are great. Really helpful with metro areas. Some areas are better than others but it depends on how the local DOT collects data. In Atlanta the system is very broad and helpful. You can see both incidents (accidents, stalled vehicles, etc.) and traffic flow. In some metro areas you don't get the flow but just the accidents that are reported. Don't fool yourself into thinking that every time an accident happens that it'll immediately popup on the screen. There's still processing time from the accident happening to someone calling it in to it being reported/noticed by the DOT to the data being distributed to the networks. Also, it's certainly possible that an accident could have been cleared and you're right at the spot where it's still being reported.

I recommend, if you know the area, that you have 'Avoid Traffic' turned off on your GPS. The problem is that it will avoid all traffic it knows about which is generally the freeways. So, for example, a freeway may have slowed to 45MPH in a section which may be OK for you getting home but if you have 'Avoid Traffic' turned on then it will route you around that and probably make your trip longer. I find it best to have that feature off and tell the GPS where I'm going every time I get into the car (unless it's literally down the street to the grocery store). The idea is that, yes, you know the way, but if a traffic incident pops up on your route it'll then give you a traffic warning icon/button which you can push and then review what's going on and make the call to have it route you around it or just push on through it (meaning, yeah, something is ahead but it really isn't that big of a deal).

Weather: As I mentioned above, basic weather comes with traffic. You'll get your current conditions and forecasts. If you want extras like maps (radar, road conditions, sky conditions, watches/warnings, etc.) then you first need to make sure you GPS has the ability to display it (not all do) and secondly need to tell the XM rep (you can't subscribe to traffic/weather via the website), that you specifically want the extra weather services.

Stock information is also sent to your GPS via this XM unit. It's included with the traffic service - actually, it may be included with the standard XM radio service. Not sure why the average person needs to know the price of a stock while they're driving but it's there.

If all you really care about is having your GPS have traffic info you're probably better off getting one of the FM Receivers and then subscribing to that for $60/lifetime of the receiver unit (the receiver is in the cable, and that is where your subscription lies). I think that all Garmin GPSs (and Kenwood units with Garmin GPS built-in) that accept the XM Radio module also accept the FM Traffic module. The reverse is not true. Consult your manual to be sure.

It seems as though Garmin is paring down the units that support this XM radio. It used to be the StreetPilot 7200/7500/2730/2820 but they've all been discontinued. There are some Kenwood head units and external GPS modules that support it but the newer Kenwood head units don't. I think they're mainly concentrating on FM Traffic and MSN Direct now.

If you're thinking about getting this and are the type of person to hold onto your gadgets for a long time (like 3+ years) then it's worth getting and paying the lifetime subscription fee. It's a lot of cash up front but it'll keep your monthly bill to [...] and you can just enjoy the XM without thinking about the [...]/month going out the window. If it doesn't work out you can always get a different XM Radio and transfer the subscription.

If you think it's likely that you'd upgrade your GPS in a year or two then I'd say go with the FM traffic receiver or MSN Direct receiver (which also has a lifetime subscription option - I think it's $99).

If you have a GPS with the ability to have traffic displayed and you either live in or frequently go through high traffic areas (check the coverage maps at [...]- follow the links; the maps are different for each service) then I highly recommend getting some kind of traffic data into your GPS.

-- I've had this for a few years...

I bought this to go with my Garmin 7200 and have used it about a week. I got it mainly for XM reception, but also for the XM traffic and weather updates. I am still checking out the usefulness of the traffic updates, but so far the XM reception has been great. I don't even have to put it on the dashboard. I keep it on the console by the shift in my Armada and still get all three bars showing full, meaning at maximum, reception. I am pleased about this because it tended to get quite warm sitting on the dash in the sun, and over time heat kills electronics, plus I don't have to have it in plain sight for thieves to notice and I don't have to have wires streaming all over the place.

Keep in mind that one reason for the steep price is due to the fact that the actual XM radio is within this circular unit....it's not just an antenna. The Garmin GPS is merely an interface for the XM receiver that is built into the GXM30 Antenna.

Also keep in mind that it does not work as an antenna for GPS reception, only for the reception of XM radio. So if you are having trouble in that area, this is not going to remedy it. You will need to purchase yet another antenna for the GPS satellite reception side of things.

Lastly, on another note, if you already have an XM radio built into your car radio, but want the XM weather/traffic updates to be pumped through your Garmin GPS, you will have to activate this as a separate radio and pay the additional fee for both an additional XM radio and the XM weather/traffic updates. You might want to give some serious thought as to whether or not you really want that feature that badly.

It does seem to be high quality, but nevertheless I plan to keep it inside my car, which should help it last longer. I do believe, though, that despite what it does it is, in fact, over-priced, so minus one star. -- Great, but pricey, device