Any simple way to fold the rear seats back?

[HDS]

Children are rear faced in cars until 4 years of age here (Finland), preferrably 5.

As it is now they fit and the chairs tilt their feet up a bit which helps, if the rear seat was folded back a bit, that'd free up some room and buy us some extra months of use before swapping cars.

We have a lot of expenses currently with building a house and related stuff so we want to keep this car as long as possible.