I have had luck by installing the driver package for the new machine while the drive is still in the old machine. Then transfer the drive.
If you are going to leave it docked in the car a CF-31 has hdmi out. Also I am wanting to think I have seen a 19 dock before (pictures only) that had a hdmi out.
From time to time there are great deals on Ebay for CF-20's. I posses both a FZ-G1 Mk1 and a CF-20 mk1 and i have to say that the CF-20 is clearly superior in every way. I installed a DELL Qualcomm 7455 that i flashed to generic and i swapped the m.2 Sata drive for a 512gb ATP one. The keyboard solution for the FZ-G1 is a joke and i have the Ikey keyboard with usb. The CF-20 is both an excellent tablet and a great notebook. The only minus i have so far would be the port cover on the screen is very thin and tends to break when you tighten the screw too hard, it kind of holds itself together when it's in closed so i did not bother to replace it for now(it would likely be cheap anyways). Also as i tried to disassemble both completely, replacing the screen on the CF-20 seem to be a bigger challenge than FZ-G1 so you might want to avoid breaking it.
Thats also what I was thinking about the FZ-G1, the lack of keyboard, I hardly ever use either 19 in tablet mode so why bother,, does the 20 use the same ssd as the FZ?
The FZ-G1 Mk1 uses a msata SSD and as far as i know some newer revision use a m.2 Sata ssd(not sure of lenght). The CF-20 uses a full lenght m.2 sata SSD.
I hope I was in the right place at the right time, I have managed to bag a low hour CF-20A5108TE and a gamber johnson dock, same as this: https://www.gamberjohnson.com/products/panasonic-toughbook-20-docking-station-no-rf all for under a grand, , just looking around for the best deal on another battery and a 2tb Samsung M.2 ssd Its all on its way to me,, Im sure once its here there be loads of questions for you guys Thanks
If you haven't already read it, check out this thread on Samsung M.2 drives. They are not all the same: A member here bought the wrong one and couldn't use it. Ended up having to sell it, if I remember right. http://forum.notebookreview.com/threads/samsung-970-evo-m-2-ssd-possible-in-cf-31-mk4.833173/ It's over my head. I don't have a new enough ToughBook to worry about it. The last page talks about the difference in M.2 B+M Key and M.2 mSATA