i also have an 03 with the hatch tray. but i did different things with it.
are you going to keep the spare tire or get rid of it for the enclosure?
what amp are you going to use?
Going to try to keep the spare. There is a decent amount of room with the spare flipped face up so it sits down in the well.
I am going to use my current Eclipse XA1000 (500W RMS at 2ohm)