Raise the rear seat back rest

[Drgrnd]

Is there a way to raise the back rest of a rear facing seat? It has a bracket that screws into the seat back and at the top of the bracket is a L shape that goes over a bar and bolts in. Is there a different bracket that would hook lower and allow the seats to be a bit higher? Or perhaps a spacer and another bar that would attach to the original bar and secure the bracket higher? Any ideas? Thanks