winisd and bbp dont take into account vehicle response, so their graphs are completely irrelevant unless you put a mic in your car and measured sweeps.
looks good man. i dont know why everyone is telling you to put 100sqin of port per cube. its a 500 watt sub for god sakes.
Bass Box Pro allows you to load Car/Room dynamics which emulate each environment..
If nothing more these tools facilitate a great way to determine group delay and cone excursion at certain freqs given an enclosure net internal volume.