rear window & liftgate covered in sticky film - oil or gas leak?
Over the last couple of weeks I've noticed that my back window was getting covered in these little droplets of what I thought was water or something, but after smearing them around with the rear wiper, I noticed that the droplets are oily in nature. They are transparent or opaque, but I have no idea what is causing them. After realizing what was happening I noticed that the entire rear liftgate is covered too.
The front windshield, the sides, and the roof of the XJ are all clean and residue-free, so I'm really confused as to what could be causing this and am concerned that it could be something I need to take care of. I don't notice any smoke coming from the tailpipe, but my concern is that maybe there is some kind of fluid that's coming out when I run it down the highway, like oil or gas or something, and it's spraying the droplets on the rear end.
I am not noticing any spots under the truck when I park it which is even more confusing.
Anybody have any ideas? I'd at least like to see if I can tackle it before I take it to the shop.
Many thanks in advance!