TomTom One User Manual page 6

Note: Your TomTom ONE does not transmit your position. You can, however,
send your position to TomTom Buddies. For more information, visit
www.tomtom.com/plus
Note: Some vehicles have a heat reflective shield embedded in the
windshield that may prevent TomTom ONE from locating your current
position. If this is a problem in your vehicle, use the TomTom External
Antenna Kit (available as an accessory).
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