Renting a car and pairing your phone up to the connected infotainment system is certainly easy enough. However, by doing so you could be compromising your privacy.

According to a report by Privacy International, the data you send to the car includes the location and contents of your smartphone, as well as your home address.

What’s worse is that the data then gets stored in the connected infotainment system and it’s unclear who, if anybody, is tasked with deleting it.

Millie Graham Wood, solicitor and legal officer at Privacy International told ZDNet that in most rental cars, “there were between five and 10 different phone identifiers. When you connect to the Bluetooth, it will store your identifier.”

She then added that “we also looked at the navigation systems: a lot of locations were stored. Places people had driven to, you could possibly link up with their name and drive there.”

In order to put together this report, cars were rented from multiple hire companies such as Sixt, Enterprise, National, Zipcar and Thrifty, and the models tested included the Audi A3 and the Nissan Qashqai.

Apparently, rental companies expect the users to delete the data themselves once they’re done with the vehicles.

“The unanimous responses were, not only is it the individual’s responsibility to delete their data when they return the rental car, the individual is further responsible for informing other passengers who connect their devices to the car that their data is being stored on the car, and not necessarily deleted,” stated the report.

Enterprise was one company that felt the user was responsible for deleting his or her information, while Sixt and Thrifty are already looking at policies to delete driver information as part of the GDPR (General Data Protection Regulations).

It’s also important to point out that the car manufacturers themselves have little to no say in the matter. When approached for comments, Nissan said that it was up to the rental company or the customer to clear the data, and that the automaker itself doesn’t have access to the car’s internal systems unless it’s fully connected to the internet.

“As this is a rental company fleet vehicle, Nissan does not have access to or control of a vehicle to carry out such a reset after each rental customer and would expect the customer or the rental company to carry out any necessary resets,” said the Japanese automaker.

So if you’re currently renting or planning on renting a car in the near future, pay attention to the type of information you share with the infotainment system – be it cell phone data or sat-nav destinations.