I've got two 10s, two 6in mids, and two tweeters all in a huge box. It make great sound, built it myself. Its about 2 inches low from the top of the back seat, and about 3 inches short from the hatch. I've got about 3 inches spare on the sides, so i don't have any space. Its well worth it though. I have a friend that put a single 15 in the hole were the spare tire goes and enclosed that. He also used the main back speakers as mids and put tweaters in the cubby. Yeah hes got a weird set up but t kicks ass. Well, I don't know if I answered your question but I hope my box demantions help any
I don't know the specs you asking for but I do know that if you messure from wall to wall and find the center that should give you the radius. I know the Tires that i have on my car are 24-5 and one tire messuring the same wil fit into the compartment so if you want to go big you could put one 24inch speaker in but you'll have to line the walling with dynamat or just go to a local carpet store and ask them for there thinnest carpet underlining. It works almost as good and is hella cheaper. To me cheaper is better when it comes to toys for my car, gives me extra mulla for my engine and such. One more thing you dont want to be drilling onto your car so you'll have to get good solid MDF wood panneling to lay on the floor of your trunk. Another thing is you need to build a vent for it to breath, if you don't your git some shitty sound. I'm rammbeling on so I'll stop, I hope I help. Good luck.