You can open Greenwheels cars with the Gaiyo app:
1. Open the app and tap your upcoming booking on the home screen
2. Open the car by pressing "Start drive".
3. The car keys are in the glove compartment. Use the PIN code (this is stated in the app on the rental details page) to unlock the on-board computer and get the keys.
4. During the rental period you use the key to lock and open the car. You don't have to do anything in the app.
5. Follow the instructions in the app.