I purchased a 2007 Nissan Altima in January of last year, and it's been great. Even though I've driven over a 5-inch high piece of wood and bombed it off of a foot high drop on a dirt road. I felt it was worth paying the "extra" for the technology package. Bluetooth? Check. Navigation? Check. Traffic information? Check.
The Bluetooth works like it's supposed to, although it is hard to hear sometimes. I can't fault the car, because the inside of a car isn't dead quiet like the commercials would lead you to believe. The navigation works well, with some flaws. I've found some aftermarket devices that allow you to override the buttons while driving, but haven't implemented them in my own car yet. Kinda scared to do that, lest I turn my car's wiring into a rat's nest.
But that isn't what this entry is about. I'm talking specifically about the XM NavTraffic feature linked with my navigation system that is supposed to allow for real-time traffic information to be overlaid on your map. It works as advertised, and indeed does show green/orange/red lines next to the road if there is traffic, and little icons if there is an accident or construction.
The problem is, most of the time the data was completely worthless. I don't know if it's on a delayed update or what, but driving up to Riverside, the roads would be all green. I can tell you from personal experience that the I-15 to I-215 to I-60 route is not "all green", especially during morning or afternoon traffic. It got so bad that I eventually started manually setting avoidance areas in my navigation system.
The accident information was also delayed. If I was sitting in traffic caused by an accident, rarely would I see it on my screen. For the times it actually did show on my screen, it leads me to make my second point-- Nissan's navigation system doesn't re-route around bad traffic or accidents!
Sure, there is an option to enable the feature, but it does nothing as far as I can tell. At least on my old Magellan GPS unit, it would announce "re-calculating route due to traffic conditions." Heck, the Magellan unit would sense that I was on a freeway and doing stop-n-go traffic, then automatically route me 5, 10, 15 or 20 miles around the block of freeway. Unacceptable that this feature is not found in a much larger (and more expensive) unit.
So eventually, it just didn't make sense anymore to have XM NavTraffic in my car. Maybe your car interprets XM's data differently (and actually avoids problems), but definitely not in a Nissan Altima.
While I'm complaining, I think I'll point out that it seems the XM audio decoder in my vehicle is not the most current decoder chip utilized by XM (even though it's a 2007 vehicle) -- this leads to lower sound quality. It reminds me of the old Delphi SkyFi XM radio I had my previous cars. I wasn't very happy with the quality at all, until someone over at XM411.com revealed to me that the newer SkyFi2 had an upgraded decoder chip. Sure enough, I bought a SkyFi2 and had a much better sound quality experience. Again, it's a shame that a "new" car doesn't have this upgraded chip.
Anyways, I just thought I'd give everyone a post-mortem on my car. Enjoy.