I don't see the need for three pieces.
The upper bars could be non-parallel with the decklid, would pivot at the top of the backlight and could have the other end pretty much anywhere on the inner upper sides of the cap. You wouldn't want to try to lift the cap with the decklid so put vertical handles on the back of the cap and lift there, using the decklid simply as a hinge.
When the top hinge over-centers it will hold itself open.
