The Maxi-Cosi Pria 85 does not need a base for installation. Therefore, you can safely install the car seat while using the vehicle seat belt. The Maxi-Cosi Pria 85 uses three recline positions in the car seat's base that are easily adjusted via a lever. Here you can see how the Maxi-Cosi Pria 85 is set up for rear-facing riding: