I acquired a Dell Latitude E5570 along with a standard Dell docking station (Dell E-Port Plus Advanced Port Replicator); unfortunately, the guide in the back doesn't even come close [even while extended] in helping align the laptop when docking. Ah, the wonders of 3D printing!! I engineered a spacer that sits on top of the wasted space and provides a little cubby for odds'n'ends.
You can put some double stick tape down to hold it in place. I left it loose as it doesn't seem to affect it and I can move the tray (quick dice tray, anyone?).