I noticed there a leak above where the drive shaft and the differential connect. But I do not see any oil on the pinion seal or around the u joint. It's just above it. Looks like something is spraying oil up towards the rear seats. I don't know what it is. Any ideas? -2001 Mustang GT
Hard to tell. It almost looks like there was a leak. And it was fixed, maybe someone sprayed some pb blaster at the flange bolts to remove them. They look like they were off relatively recently.
Did you have any other fluid leaking and maybe getting slung around the driveshaft or pinion? In the 1st set of pics the seal looks dry at that angle.
A little bit out oil will make a huge mess due to the pinion spinning. Check the fluid level, top it off, and check it again next time you have it up in the air.