When I bought my car I took the trunk liner out to replace the battery and I saw a small brown puddle underneath. I assumed there was some water intrusion (although it was more black than the reddish brown of corrosion) so I cleaned it up and decided to keep an eye on it. After a few heavy rain storms and car washes I checked again and there is no new water at all. I took a picture of the stain left behind from the first puddle. It looks like an oily sealant around the studs or maybe still corrosion? Also what are those whitish plugs in the trunk floor?

 

The white plug is for shipping / setup from the factory. Being unplugged now is correct.
My guess on the gunk is that something spilled - possibly a leak from the tire goo.
Regardless, it's about the right time to check your goo bottle's expiration date.

 

That's the transit relay plug as posted above. There should be a small cut out somewhere nearby to "plug" it in and keep it from wandering around.
Here is where it plugs in on my XJ so different car but same plug.



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I think he is talking about the 2 white plugs in the floor of the trunk - and I don't know what they are for. I have a question about the expiration date on the tire goo - I looked on mine and cannot see a date anywhere. Can someone tell me where on the bottle it is supposed to be?

 

The white plugs look almost like caulk or something. You do know that a lot of the assembly of our Jaguars is actually done with an exotic, high strength adhesive. Perhaps that is some residue from the trunk section being glued down to the section below ? I'd probably not worry about it but keep an eye out for any future reoccurrence of whatever the leak was.