It's dead of winter, the back windshield is covered in salty grime, and I'm out of windshield washer fluid. I went to look for the reservoir to fill up the back, but for the life of me I have no idea where it's at.

Does anyone know where to fill up the back windshield washer fluid reservoir?

 

It runs off the front one in the passenger side wheel well , under the hood ... If te fronts are working and not the rear the rear can be froze or clogged

 

That's what I was afraid of. The front one is filled, but the back won't spray. I was hoping that I was just a moron and couldn't figure where to put it. But alas, the simple solution it is not. Any tips on getting it unclogged? Thanks for the help!

 

If it's frozen I've used a cup of hot water before , but be careful to not pour it directly on the glass (could cause cracking)...
If you think it's clogged I've used a bread tie wrap and strip the plastic back and use the wire to clean the opening

 

If you still have summertime washer fluid in, that could be the problem. I tend to never use summer fluid because it is too easy to carry it over to freezing weather. Try dumping some rubbing alcohol in the reservoir, but if it is summer fluid frozen in the line, you are screwed 'til you can put the car somewhere warm.