That's really useful. I was using it for bodywork. I contemplated doing the floorpan with it because it does get water in there from time to time (a door seal or something that I can't determine) - and before I used Hammerite, which was OK but didn't seem to stop the rust breaking through if water sat there.
I've done a repair on a wing. A hole, which I dug out, scraped, wire brushed and then painted with POR-15. I have then used filler and gauze (Sorry

) to fill the
small hole and again, put a coat of POR-15 on top of that to stop the edges being exposed. Finally, a thin skim of fine filler on top, sanded, primed and then top coat/lacquer.
I'll let you know how it holds up. I do agree though that it is fab on suspension parts and even when they are pitted, it forms a very nice shiny black bond. Looks good at least and from reports I read, seems to last forever.
There's a great youtube channel (Project Farm) with a guy who just tests stuff without being sponsored etc. He's really good and when he tested POR-15, he was quite impressed by it. I'll see if I can find the link.
Here it is:
https://youtu.be/Ag46YUovPUcThanks again for the comments and advice.