If you have a hatchback model, your vehicle has a retractable safety belt in the center rear seating position.
Here is how to use the center rear safety belt.
The shoulder belt may lock if you pull the belt across you very quickly. If this happens, let the belt go back slightly to unlock it. Then pull the belt across you more slowly.
If the belt stops before it reaches the buckle, tilt the latch plate and keep pulling until you can buckle it.
Pull up on the latch plate to make sure it is secure.
Make sure the release button on the buckle is positioned so you would be able to unbuckle the safety belt quickly if you ever had to.