Dear Tom and Ray:

Do the different car companies offer GPS units that give different styles of navigation? I have a 2013 Nissan Rogue and have used the factory-installed GPS, but I find that it gives strange directions. When I first got the car, I used the GPS to navigate me to already-familiar destinations so that I could get used to following its spoken directions. I found that often, the GPS would direct me a bad way (like going at right angles to a destination instead of a 45-degree angle). Once, it directed me to a familiar destination that should take about an hour, but the GPS directions indicated that it would take an hour and a half! I've tried changing the route selection to "economy," "shortest" and "quickest," to no avail. I never had this problem with my brand-name portable GPS. Do I have to choose my next car based on the accuracy of the GPS unit? Please help, as this is driving me (pun intended) crazy. Thank you very much.

-- Susie

TOM: Different manufacturers absolutely use different GPS systems, and some are much better than others. The maps themselves, the software they use to operate and the user interfaces all are different.

RAY: Traditionally, the built-in GPS systems were the best. They're well-integrated into the car, they override the sound system when necessary, and they're usually displayed on a large screen, or even in a heads-up display projected through the windshield.

TOM: The biggest disadvantage of the factory-installed systems is that they've been very expensive. Crazy expensive: You often had to pay $2,000 to get a navigation system, along with whatever other less-appealing items were packaged with it.

RAY: And when the maps needed to be updated (every couple of years), you could be hit up for another $200-$300 just for an updated CD-ROM that you had to install yourself, sometimes with difficulty.

TOM: So lots of people opted instead to buy portable, stand-alone GPS units that could be attached to the windshield with a suction-cup-based mount. These are made by companies like TomTom, Garmin and Magellan.

RAY: These portable units cost as little as $100, and they vary in quality, too. But a good one with a larger screen, like the highly rated Garmin 3490 or 3450, can be had for a few hundred dollars.

TOM: So a few carmakers, especially on some of their less-expensive models, decided to do what consumers were doing. Instead of installing the more-expensive, larger, integrated units, they incorporated these cheaper, smaller, less-sophisticated GPS boxes. That's what you got in your Rogue, Susie. You got a cheap little GPS.

RAY: A final option on the market now is your smartphone. A lot of people are abandoning GPS units altogether now in favor of their phones. Google Maps, which is available for free on most smartphones, generally provides excellent directions -- as long as you don't mind Google knowing not only everything you've ever searched for on the Internet, but also your minute-to-minute whereabouts.

TOM: This may be the next area to "take over" the GPS function in cars, as companies like Apple start to offer software that allows drivers to mirror their phone displays and interfaces on vehicle entertainment systems.

RAY: In general, though, these days we'd recommend a highly rated portable unit for most people. The biggest advantage of the portable unit is choice. You can shop for and buy one that suits your needs, is easy to use and provides good, reliable directions. And most importantly, if it fails, or becomes out of date (in terms of information or technology), you always have the option of tossing it in the garbage and buying another one.

TOM: That's not the case with a built-in system, where you're often stuck paying $300 for an update whether you like the system or not. A customer of ours had a nightmare experience with Honda, where they sent her the wrong CD update, and then the dealer refused to refund her $300 or give her the correct CD, sending her on a wild goose chase to get it back from some company in Colorado that apparently supplies Honda's navigation maps but never answers the phone, and when it does, can't find both cheeks in the shower.

RAY: So if you're not happy with the cheap GPS system that came with the Rogue, Susie, just don't use it. Buy one of the Garmin Nuvi 3000 series (or 2400 series) units from someplace that gives you 30 days to return it, and try it out. If you don't like it, try another one. Happy navigating!