Flyht Pro Eco Rack 9,5" 3U Double Door

I want to like this case I really do. It's relatively well made and comes with rack strips front and back and a decent amount of hardware. Aluminium frame with some sort of medium-weight corrugated plastic panels.

But it has a fatal flaw. You can't get it "square". Whatever I try this still wobbles when on a flat surface. I've installed some Sennheiser EW radio mic receivers in it - good solid German products with metal chassis and rack mounting. On the back I've got Flyte Pro metal rack panels to hold the XLRs and antenna BNCs. But try as I might, loosening and nipping up the screws on each side, I cannot get this case to stay square so it doesn't wobble. I can get is square/flat to start, but as I gently tighten the rack screws it starts to wobble again. It's driving me mad.

I think I'm going to have to buy the plywood version instead, which I'm wishing I'd done in the first place. I was aiming for a slightly less-heavy solution which is why I chose this "plastic" version. But it's caught me out.

Edit to add: Much like the comment on the non-ECO version of this case, the laminated label on this ECO product is also positioned such that if you stack these cases the label coincides with the position of the rubber foot. So stacking will also cause the upper cases to rock. Thomann should fix this school-boy design error on all of these cases.

So: great but terrible. Such a shame.