Cracked tambour housing.
If you have good access to the back of the crack you might try putting a good "tooth" on the plastic, (tooth= aggressive sanding or grinding with a coarse medium) and using an epoxy glue in conjunction with fiberglass mat.
I imagine that the back of that plastic is so smooth and slick that getting glue to stick without a good sanding is highly doubtful. A failed glue joint sucks to no end.
If you can't get to the back, I would consider learning to ignore the crack. It will be difficult to achieve a solid and good looking repair on that piece without extensive refinishing of the entire piece, and even then, preserving and/or recreating the texture will be next to impossible.
The fact that I am opinionated does not presuppose that I am wrong......