Because the iPhone gives no is no indication of GPS signal strength or accuracy to compare with the TomTom's figures, it is difficult to tell exactly how much more accurate the TomTom receiver truly is though. During our testing, we noticed the most dramatic improvements in urban canyon environments, such as San Francisco's Financial District, where the TomTom app dropped signal less often while in the cradle than it did while navigating without .
The TomTom Car Kit's integrated speaker is much louder and clearer than the iPhone's, which makes a huge difference when trying to hear turn-by-turn directions over road and wind noise. When the TomTom gives the navigation app text-to-speech for street names in its next update, the loudness and clarity of the speaker will be of even greater value.
The speaker also comes into play when making hands-free calls. While the verbal turn-by-turn directions are sent through the dock connector before being piped through the system, the hands-free calling system must be paired via Bluetooth. After punching in a quick four-digit PIN on your iPhone, calls can be made through the Car Kit's loudspeaker and integrated microphone. Up to eight phones can be paired with a single Car Kit, but only one can be used at a time.
The TomTom Car Kit also charges your iPhone while you drive, so your battery won't be dead when you reach your destination. The line out connection lets the iPhone pipe music through your cars stereo. Unfortunately, there is no auxiliary audio patch cable in the box, and only music, not the turn-by-turn directions, can be piped through the car's speakers.
TomTom's Car Kit for iPhone was designed and optimized for use with the TomTom app for iPhone. Unfortunately, the Kit doesn't come with the app, which must be purchased separately. If you don't want to buy the paid app, a free TomTom car kit tool app is available for download in the iTunes Store. The free app displays GPS connectivity status, GPS coordinates, and other miscellaneous information about the cradle. It's a neat little app for making sure that the TomTom Car Kit actually works, but it's fairly useless for point-to-point navigation.
To get the turn-by-turn directions that are used on all of the promotional materials, you'll have to drop an additional $99 on the paid iPhone app, which we've already reviewed.
During our testing, the TomTom Car Kit for iPhone did a very good job at addressing some of the issues that we've had with the iPhone's GPS navigation. The speakerphone is loud and clear, the hands-free calling system is easy to setup. While difficult to measure, we did notice that frustrating GPS signal drops happened much less often with the Car Kit in place.
The TomTom Car Kit for iPhone carries an MSRP of $119, but that price is more than a little misleading. For the kit to be useful, you need to add $99 to that price for the software. So you're actually in about $220 when all is said and done. At that price range, you're above the $200 MSRP of the, a standalone portable navigation device with a very similar feature set. However, the TomTom Car Kit features Bluetooth hands-free calling through the connected iPhone and online POI searching using the phone's data connection, features that can't be duplicated in the TomTom ONE series.
Additionally, users will only have to carry one device to and from the vehicle using the TomTom's iPhone solution and only plug one unit in for charging while navigating, which is a tremendous pro for users with limited bag and dashboard space.