Rear window leaking on 179

Check the screws around the frame. I noticed that several of them in my 179 were loose. Also, the rear window had been caulked, but whoever did it did a lousy job. I recently redid it. Instead of using the "clear" silicone, I got a tube of black silicone and was careful to caulk and clean up around it so that the finished job looks much better. This is a design problem. Forest River is mounting a flat window on a curved surface. Because of the curvature, it is hard to get the seal pulled up tightly all the way around.

Yes. I removed the original silicone, which had gaps and holes. Then I cleaned it up with rubbing alcohol. I tightened the screws. The ones at the top right (looking from inside) were the ones that were loose. When looking from the outside, it was evident that the window rubber seal was not pulled in evenly all the way across.  I made sure all the screws were tight, then did the silicone caulking. From what I understand, it is best to do as was done and caulk the top and sides but leave the bottom open.

Forest River might have done better to put two windows, one on each side and left the back wall intact rather than putting a flat window on a curved surface. Alternately, they should find a way to make that part of the back wall flat so that the window isn't being mounted to a curved surface. That is, unless they can find a way to make the frame curved to sit against the wall better.

I think it's just a compressed rubber seal. If I had one leaking out of warranty, I would clean it up and put a nice fat bead of silicone on the outside on both loops of the frame. You have nothing to lose and more often then not, it works great. 

I don't have a leak, but will check the spoiler also. The sticker by the door states that all seals should be inspected every 90 days. I guess that is part of the checking.

Ditto! should check all the areas on a regular basis.