I simply bought a piece of 1-inch thick foam, tapered the lower edge, and covered it with a gray fabric remnant. It hangs by straps from the headrest posts.
Very comfortable, easy to make, looks good, and works!

 

I sit very upright, and the headrest in my 2010 Fit has really bothered me since I purchased second hand in 2012. I finally couldn't take the discomfort any longer, and took a chance buying a front seat headrest for a 2007 Honda Accord off of eBay. It works! Here is the item I purchased:

Front Seat Headrest 2007 07 Honda Accord | eBay

Fits perfectly, and solves the problem. And matches the gray interior well enough.

Hope this helps other suffering Fit owners.

 

Do you have a side by side image of the head restraints by any chance? It looks similar to the original ones on ebay and I didn't want to buy them if they are near the same. But good for you to give it a try. The new 2015 Fit head restraints are less raked forward but a Fit Freak member complains of back pain on his new Fit 2015 being a back problem too.

 

Per request, here are two photos of the original headrest and the 2007 Accord headrest I bought off eBay. I was trying to figure out the best way to show the difference, and think that showing them in the car would be best. First the original:



And here is the 2007 Accord headrest. The seat position has not changed at all.



There doesn't appear to be much difference. However, look at the front bottom edge of each headrest. Notice that the original bottom edge overhangs the seat by about 3/4", while the replacement headrest comes down in back of the seat by about 3/4". That 1 1/2 inches makes a world of difference.

 

Wow looks great and I would think it would make a difference. Looking for a set as we speak. Thanks so much for posting photos.

I noticed without using my BackJoy seat pad my back hurts so I put the Back Joy back in and my back feels better, I never would have thought it would have made a difference and I don't think it's mind over matter because I don't like adding to any seat. My old car had a lumbar support so my back must have gotten used to it. The Backjoy seat pad puts the curve into your lower spine as though you used a lumbar support.

http://www.fiftysense.net/reviews/backjoyPic.jpg

 

I bought the 2007 accord headrests and they are 3/4" too narrow to fit into the slots. Did you bend them?

 

Grunthaner, no, I did not bend the posts. They are pretty thick steel, so I don't think they are bendable. Sorry yours didn't fit. Sounds like you may have gotten the wrong model some how. Does it look like mine?

 

Yes most likely wrong one. I am trying to get them to take them back now. I got them on eBay a used car parts shop. I'll keep trying.