I dont promise that it will fit perfectly or the way you want it, but I liked it... until I quit and stuck with my ugly box I bought from the store 
this is how it looked in the trunk
all measurements are in inches... and the thickness of the wood I used was 3/4 in
and make sure how you are putting all the pieces together... the difference of mounting the ceiling inside of the box and outside of the box is 3/4 inch of a difference (it was 3/4 of a difference because I used 3/4 inch thick wood)

this is how it looked in the trunk

all measurements are in inches... and the thickness of the wood I used was 3/4 in
and make sure how you are putting all the pieces together... the difference of mounting the ceiling inside of the box and outside of the box is 3/4 inch of a difference (it was 3/4 of a difference because I used 3/4 inch thick wood)