Dockable ethernet is do-able, but tricky. You need to mount an RJ-45 plug (with the snap-tab broken off) in a very-well-supported, stable manner behind the sled. Some metalwork is probably involved.

Another (easier) thing you can do is to just dangle an ethernet cable behind the sled somewhere. Secure it in such a way so that (a) it doesn't fall down and get lost inside the dashboard, and (b) there's enough extra length for you pull it out of the docking cage a tiny bit.

Then, when you want ethernet, you just reach into the cage, pull out the wire, and plug it into the empeg before inserting it into the sled.

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Tony Fabris