https://www.edmunds.com/car-technology/should-i-buy-a-cars-factory-navigation-system.html
In their infancy, navigation systems were an expensive option reserved for luxury cars. Today, navigation systems are nearly ubiquitous, even on economy cars. Furthermore, there are now lots of alternatives, ranging from portable systems to smartphones to aftermarket stereo systems with nav.
Which one should you buy? What are the advantages of each setup? Which is less expensive? Do you even need one given that your phone probably has one or more navigation applications? Here are a few things to consider so you can choose the system that’s right for you.
Aftermarket In-Dash Navigation Systems
Pros
More features: These are geared toward techies and audiophiles who want additional
features while maintaining the sleek appearance of the factory unit.
These aftermarket navigation systems have entertainment features that
you might not find on most factory systems, such as DVD video playback,
Apple CarPlay, Android Auto and Pandora streaming.
Better screen: Compared to older vehicles with more basic stereo systems, aftermarket navigation screens are a significant improvement. Many systems will have higher-resolution screens with animated menus and flashy colors.
Customizable: An aftermarket navigation system is designed to be the centerpiece of an upgraded audio system that allows for user customization. Some models allow you to customize the menu icons, colors and backgrounds. You can also add extra equipment, such as a backup camera or Bluetooth capability, if your vehicle didn’t already have it.
Cons
Price: An aftermarket in-dash nav system can sometimes cost as much as the
factory unit. The prices start around $250 and can go over $1,000, plus
at least another $250 for the installation.
Theft prone: Thieves know how much these units cost and how easily they can be removed.
Not fully integrated: Although the system sits in the dash and is thereby more integrated than a portable unit, it will never look exactly as if it were part of the car’s original design. This may or may not be a good thing, depending on your point of view. And while you’ve gained new features, you may lose steering-wheel functions such as music volume and track controls. Some companies sell a special adapter that can restore that functionality. The part costs about $40, plus installation.
Smartphone Navigation Systems
Pros
You already have one: Factory-navigation skeptics argue that smartphones are an alternative
to an expensive factory system, noting that phones already have a map
application, and that’s all you really need. Given the quality of the
maps from Apple and Google, we’re inclined to agree that they are good
enough for most people. That said, there are a few limitations to keep
in mind. More about those later.
Traffic data: In many cities, the fastest way to get from A to B isn’t necessarily the shortest path; it’s the one with the least traffic. Smartphone apps have excellent traffic data and access to Waze, the community-based traffic app. Factory nav systems may have live traffic data, but you have to pay for a subscription once the trial has ended.
Current maps and points of interest: Smartphone maps will never be out of date, and any updates are always included. The same goes for the names and addresses of any points of interest you want to visit.
Convenience: Smartphones let you input an address as you walk to the car, leverage your contacts for their addresses, have a calendar app to remind you that you need to leave at a certain time, and then route you there. All those things happen in a faster interface with typing that’s easier than the input method required by other systems.
Integrated smartphone options: Apple CarPlay and Android Auto offer the convenience of smartphone navigation with the integration and safety of a built-in system. They offer the convenience of smartphone navigation but with a larger screen display. That reduces the potential for distraction.
Cons
Distraction: Unless you have Apple CarPlay or purchase a car mount for the phone, it
will most likely sit in a cupholder. And since you’ll have to take your
eyes off the road to check the directions, this can be just as much of a
distraction as texting while driving. The mount itself can cost from
$20 for a basic unit to $100 for a do-it-all mount that will charge the
phone and boost the audio and GPS signal.
Spottier reception: Most of the native map applications rely on a cell signal for their map data. If you lose cellular coverage, you may find yourself unable to use the maps and directions. Apple and Google offer the ability to download certain maps for offline use, but it takes more preparation and hard-drive space on your phone (up to 1.7 GB on Google Maps). And without a cellular signal, you won’t have access to traffic info, alternate routes or lane guidance.
Battery drain: Running a navigation application on a smartphone can sometimes take a toll on its battery, which makes carrying a phone car charger more important. It can also be an added cost if you don’t already have a charger.
Source: Edmunds.com