Yeah, just a precisely machined block of MDF, that installs with a single screw through an existing opening in the back of the dash mount. One then inserts a suitable length of cat5 cable through, crimps a fresh RJ45 connnector onto it, and then pulls it snug into the locating groove. Mates perfectly with the empeg every time.

For a single one-of construction, make a block to fit snugly into the area behind the empeg's ethernet jack, and drill an oversize hole for the ethernet cable to pass through. Insert the empeg, insert the cable from behind, and then fill the gaps with some hot-melt glue. Once it hardens, everything should remain exactly aligned. Easier to do with the car sled out of the dash, though.

For Wifi, just plug a Wifi travel router gizmo into the other end of the cable, and find +5V power for it somewhere.

Edit: I just now had a look around for one, but it seems even my "last one" is gone. Found the Home Dock jigs and a couple of unassembled docks, with their own version of the MDF ethernet block, but not the version to fit a car sled.

Cheers