If you had to choose

[Jessica]

IB is too finicky 

[3vil]

Is your friend ok with cutting up the rear deck? Ported box with port through deck, sub facing forward, box sealed to the ski hole to make it a parallel 6th.

 

 

 

And since I'm guessing that's more tuning work than you want the headache of, I voted 4th in the poll.

[Jessica]

like the poll says, ski hole or in da trunk

[Karkov]

I haven't voted yet but I'm curious if for the ported option would it be subs facing forward port facing forward and sealed off?  port firing into/through ski hole?  This is what I would pick....

[Karkov]

Damn, LOL, 8 votes and I was FIRST to pick ported.  Looks like you should do 4th firing through ski hole.  =)

[Joe X]

 

The ski hole cross sectional area limits the size of a project due to limited port area, 4th bandpass projects need greater port area than a standard ported.