Correct! That's exactly what I did - with one caveat:
I found that superglue wasn't enough to hold the metal-trays inside the indents of the tablewar, plastic trays (they're almost like a frame, with a depression area inside of it - i had my metal trays cut to fit in the indent). The superglue sometimes wouldn't hold well and other times (when it held on the corners) the tray would 'bounce' up slightly in the middle. Superglue didn't seem to just hold it still.
This caused a problem when driving on bumpy roads: the metal-tray would bounce-up a bit and jostle the trays on top. Even though everything was magnetized well, repeated bouncing would shift them and big ol' bumps (on a car with bad shocks) would probably set models free of their base. So to fix this, i mixed up some epoxy and just put a bead where the tray met the plastic. Perma-seal! I didn't have to go all the way around, but just on the 4 corners and mid-way on the long side. Enough to make it immovable.
I also used epoxy to hold the magnets to the bottom of my trays. I found that rare-earth magnets would rip free of the plastic tray if only superglued. So a bit of epoxy to set it in made a permanent bond.
-luke