Max has asked the Autoblog crew which aftermarket nav system, in our honest and infinitely wise opinion, is best. Uh… we honestly don't know. Most of the nav systems we've used in the past are DVD-based units from the factory. We don't have much experience with the suction-cup-to-the-windshield variety.

We would definitely require expandable memory and a subscription service for updated maps, traffic and weather info. We dig TomTom's Plus service because it provides all of the aforementioned necessities and additional navigation voices to perk up your trip to grandma's house. A touchscreen and mounting system would be nice, as well.

Since we're not the experts on this one, can any readers out there recommend a unit for Matt?

Also, check out this Ask Engadget post on virtually the same question.