Yes. The opening on the 09-10 is wider in the middle and tapers on the top and bottom. The center is about 41", 42" if you pull the plastic panels, top is about 35 and bottom is about 32 or so.
I checked my son's 06, and the diagonal is about 45", maybe 46" if you remove the plastic panels.
Pics of a piece of 4' wide masonite board in my 10 GT hatch opening:
You can see how the opening is shaped:
My son's opening: