Mount PCIe cards into mini racks

Some cases (like the MyElectronics Mini ITX 10" case) have room for half-height cards, but that takes up a good amount of space.

It would be nice to find a way to securely mount a PCIe card _horizontally_, with the ports either out front or out back, using either a PCIe riser or (my preference) oculink. Using oculink, you could use an M.2 to oculink adapter and pass the wire through to a 1U or 2U tray that would hold something larger like a GPU, 10 or 25 GbE network card...

A 3D printed solution might be the best option.