Help with 4th order design for 2 Sundown SA 12's

[jessdabest77]

First of all,Happy New Years guys. I have done many ported boxes for these subs but now would like to try a 4th order box on them. Subs are two Sundown SA 12's on Sundown 2k amp. Car is 2010 VW Passat. I want to the port coming out from the center arm rest console. Space available is, 28.5" Depth x 15.5" Height x 30.5" Wide and available space for port opening is, 7.75" X 15.75" X height. I need help with the whole design from box size, port size and depth, and any other useful info. I can build it just need the design, thanks in advance and can't wait to build it.