Get rid of that stupid minimal tray. Cut a few panels from 1/4-in plywood to line the insides of the cubby and bottom. Cover them with black fabric or paint them. Put some velcro on the rear of them and on the corresponding areas on the inside of the cubby and bottom.
There you go. Plenty of space, looks good and is totally undoable. You can also cover the top holes where the tray would attach with some felt strips - just glue them on. You can even do away with the side panels and just velcro on some thick fabric; the plywood simply allows you to get a wrinkle-free look.
I simply don't have the tray and dump stuff inside the cubby. I will be doing the above though, just to be a correct D90 owner.