What's the deal with these thick headrests in new cars? They're uncomfortable.

never seen them, maybe you could take them out

I hate headrests that are not like mine which is made as part of the seatback ; the seatback  is just tall in other words.  The others force your head forward so you are sitting like a turtle creating back and neck trouble.  That is unless you are 6'5".  I took if off of my mother's car when I drove on a trip with her to visit family.  It was a PT Cruiser and I absolutely refused to deal with it.

Every year they ruin cars a little more as to comfort.  You can thank sue-happy lawyers.