No there's not layouts for it. It's all custom work. Took hell of lot of time to make it and its still not finished yet, I never got a change to make the grill for the spakers in the shape of the Audi Rings (partly because I don't have the time to work on it anymore and because i'm lazy. Come to think of it I don't even know how I was able to put so much work into this install. )
Basically what I did was make a templete out of carboard first. I cut out 4 - 12" circles and then place them in the trunk to get the basic shape and taped them together. Then I cut out rings out of mdf board in the same size. Used the templete to get the proper shape. It isn't proportional to the actuall Audi rings, the trunk would need to be wider for them to be correct. Plus the enclosure fits very very very tightly in the trunk and it tappers in the back. I don't have anything holding it in place, its just sitting there and hasn't move an inch.
Then I make a second templete for the back and cut out the mdf board using the templete. there were 3 pieces. 2 circles and 1 old shape that went in the middle, same with the front rings.
Then used fiberglass to put it all together. This is just the gist of it. It was a long process and if I went into detail this post would be over a page long.
Oh, and I don't know what the size requirement for the type x are, but it they need more air space then the r's, then I don't think you'll be able to accomplish the same enclosure, because of the size of the trunk, unless you make the cylinders very long, but then you'll have no trunk space left.