I popped off the lid, de-soldered the existing excuse for an antenna, and replaced it with a pigtail I had laying around. The pigtail was intended to be used in a desktop using a mini pcie card in it, so I chopped the connector off the end and stripped it down in similar fashion to the OE cable. I popped the hole next to the GPS antenna out with a screwdriver and the new RSMA connector fit perfectly. I put a reasonably large antenna on the unit and not only could I see the router from a house on the other side of the street and down a plot, but I was able to connect and pull internet through it.
I could put a smaller antenna on the connector and install it as is, but I intend to use an extension cable like this to get better signal from somewhere besides the radio slot of my car.
Next up: Heatsinks and a fan!