I'm thinking about it too, but 15" have kinda different bolt pattern (4, not 5 bolts, and my 3d skills suck), also - I'm following Japanese Volk Rays site, and there's no 15" with basic FM4 shape - only the TE37V, smooth-shaped ones. (There's also no 19", but shh...)
#Mario :
yep , too much versions there. Adjustable offsset instead normal/deep/deepest ?
All these will have adjustable offset.
And about the thing you told - I could do adjustable dish, but it's a little hard to make it actually work.
