Carmakers have been collecting and keeping data about where drivers have been.
A US government watchdog has found that owners of those cars cannot demand that the information be destroyed.
The Government Accountability Office found major automakers have differing policies about how much data they collect and how long they keep it.
According to the Detroit News, the carmakers collect location data in order to provide drivers with real-time traffic information, to help find the nearest gas station or restaurant, and to provide emergency roadside assistance and stolen vehicle tracking.
The report found automakers had taken steps to protect privacy and were not selling personal data of owners, but said drivers are not aware of all risks.
Senator Al Franken said more work needed to be done to ensure privacy protections for in-car navigation systems and mapping apps. He plans to reintroduce his location privacy legislation sometime this year.
As cars get smarter, there is more than just navigation systems creating interesting data. Event data recorders, known as "black boxes," store data in the event of crashes. Transponders like EZ-PASS transmit location and are used in some instances by law enforcement and for research. Some owners also agree to monitoring of driving habits to qualify for lower insurance rates or to keep tabs on teen drivers.
A contractor that works with three of the companies told the GAO that when a consumer requests services, information such as location, vehicle information number and other information may be kept for up to seven years.