Port size

treman03 said:

Now leaving the volume the same and popping the trunk lid the bass doubles, maybe triples.

Click to expand...

This is an issue with standing waves.   An oldie but goodie here: http://www.teamrocs.com/technical/pages/aiming.htm

Short answer is to experiment with location and aiming of the box in the trunk. 

Also 2" round port does sound very small.  I'd guess after a couple hundred watts the port will unload and perform very poorly.   As far as just making the port bigger you start really cutting into box volume which will hurt output and performance, and of course those "shallow mount" type woofers are generally rather limitoued to begin with.

Anyway, start with just playing around with location and aiming then if you can't get where you want come back and post precise box dimensions and see if someone can help you figure out a fix for that smalll port.

A 2 inch port is way too small for that much cone area and shallow mount subs are pretty much all garbage to begin with. That port is so small it's causing the whole box to act like a leaky sealed box rather than a properly designed ported box.