DC Level 4 15" Enclosure Ideas

[GorillaFIngeRs]

I have tried to find posts of similar builds. I am going to be upgrading to a level 4 15, I will be running 1600w to it, my avail dimensions are 30w x 18d x 16h. I want to tune low around the subs fs which is around 31hz. Im looking for help on ideas for port size, sub placement ( deeper box sub middle, elongated box w/ sub to one side and port on the far side?) just looking for your guys personal experience with different port designs, i will def be using a slotted port. I am thinking around a 3" port from what i've looked into but open to anything.

My car is a 2011 toyota corolla for now so i'm looking for this to be a removable box and just basic rectangle, square trunk box.