The rear seat back(s)*1 can be folded down to accommodate bulkier items in the trunk .
To fold down the seat:
To lock a seat-back upright, push it backwards until it locks, so that the red tabs in the release lever go down.
When returning the seat-back to its original position, push it firmly back.
Make sure that the folded seat-back does not press against the front passenger seat, as this can cause the weight sensors in the front passenger seat to work improperly.