Ryzen

Pleasant day, Yesterday I decided to get 2 sundown X8 V2 Subwoofers for both of my vehicles. I would like to get an enclosure for it. One tuned to 36Hz and the other tuned to 38Hz. I have posted pictures of the dimensions that I have to work with. Both vehicles are the same. Space I have to work with is 42"W x 18.5"D x 16.5"H Really looking to start this build tomorrow. Any help would be greatly appreciated! Cheers!