Turned her sideways and spent hours with a wire brush on my drill.
The areas that have been soaked in transmission fluid or motor oil comes off easily.
So I will probably leave the factory under coating that is still adhering and just clean up and re-coat the
areas that need it. I can reach most of the under side with the drill and brush, but I'm thinking of getting
one of those cheap Harbor Freight spot blasters to get up into the corners and crevices.