Does anyone know how wide the hatch area is in the vibe and the matrix?

I am selling a custom made box with 3 10" subs. It is made for a mazda 3 but it should fit a matrix and vibe as long as the hatch area is 40" wide.The subs are 10" audiobahn natural excursion AW102T subwoofers rated at 450 rms per sub.The box consists of 3 individually sealed chambers...