This section is devoted to GPS units that are specifically designed to be used in a vehicle. They are easy to install and can be moved between vehicles if desired.

1. How do these units compare to ones that come in a car?

They use the same maps as are available for in-car systems. They generally have smaller screens and a more limited POI (points of interest) database although this varies with different units. They feature portability which provides full function door to door routing and voice instructions. They can be removed and used in other cars or inside your home for trip planning.

2. How do these units compare to handhelds that auto-route?

These units generally have a bigger screen and are designed to be mounted in a vehicle. They offer voice guidance instead of beeps. They are often faster at route calculations than a handheld unit although this varies. Handheld units have batteries for use outside the car which is missing on most of the units in this category.

3. How do these units compare to PDA's with a GPS attached?

Vehicle units have an integrated GPS so the user does not have to deal with an add-on. The interface is specific to GPS use which usually means optimized keyboard design and a simpler single function interface. They are generally missing the functions of a PDA such as address book integration. Vehicle units feature a larger speaker and clearer voice that is typically available from a PDA. They are also complete solutions with nothing further to buy while a PDA solution may need extra cables, vehicle mounts, audio solutions, etc.