Toaster under cabinet?

In space gaining tough I am thinking about toaster/oven mounted under cabinet.
I think I have seen such gizmos in the past, but checking the net now - I did not find any design for such mount.
I understand oven gets the exterior hotter than microwave ovens that are mounted that way quite often, but did anyone tried to mount it this way?
I have some fiberglass/cement siding that I would use as spacer.