Yes, up to three cars can be connected to one user. You need the corresponding number of devices.
However at this time you'll need to log out and in again in order to exchange between cars.
To do this proceed as follows:
1. Order a device on autoSense.ch or buy one at amag.
2. Upon receipt you can do the following:
3. Go to your App and disconnect (More -> User -> Disconnect)
4. Click on Start
5. Tick "I already have a device but I want to add one more" and log in
6. Click on "Add a new car/account"
7. Enter the 9 digit number you've received with your device. Then also the Serial number of the device and the VIN (Vehicle Identification number)
You'll always need to log out again to change between cars.