yea I can make one if you know what you want. I dont have the time right now to do all the testing to get you the best box. Making a true SPL box isnt a simple process. It requires ALOT of trial and error. Because you cant always account for cabin gain you get your cars resonant freq. Then you model your sub out using winisd or some other program to find the correct tuning freq, box volume and port area to have the enclosure peak at that freq. I think I am going to write a short tutorial on this sometime soon. I have been asked multiple times about this and maybe that will clear up some of the questions.