I noticed this huge spot on the cargo area carpet when I first got the Disco. Just figured it was a nasty stain, no big deal. All the rear seatbelts were tucked under the seats when I got it as well. After I routed the belts through the openings, I started to notice that anything that touched the belt straps would absorb some nasty oil stains right off em. Ruined two good sweaters. So I put it together, then figured maybe the PO had a little oil spill back there, but I kinda feel like the spot is getting bigger! Is there someway that oil could be getting up here from underneath? I figure probably not, but I just wanted to ask

 

That black padding is literally a sponge PO probly spilled oil and it soaked into that sponge, I would say pull the padding and replace it or do without like me it is just a little road noise with it removed then remove and scrub that carpet and seat belts, depending on the oil type it can be near impossible to get out completely

 

Pull out carpet and padding. I replaced it with a rubber Matt from tractor supply and cut it to fit