1997ThunderbirdLXV6
PostWhore

Step 1
Obtain factory tilting headrests, such as Town Car long wheelbase rear, pre-99 Continental, etc. (preferably any model with leather which tends to keep the inner foam cleaner).
My local junkyard charges $6.99 per headrest, so this is a budget friendly mod.
Step 2
Remove your headrests. They are held in with metal spring clips. It's easiest to simply remove the upholstery, but you can also disengage the clips using a screwdriver - your choice. For illustration, this is the clip, but removal of the bases is not necessary:
Step 3
Swap the guts of the headrests. The tilt inner body (plastic) is slightly taller than the non-tilt (metal), so you must also swap the foam, so that foam and inner body fit together. Junkyard cars can be dirty. Check the foam before you buy; even if clean, it doesn't hurt to spray the foam with disinfectant, etc.
Everything is super tight. Take your time. Opening the headrests is particularly tedious.
Note the two screws: they are used to make the tilt harder or easier.
Step 4
Put your headrests back in and enjoy!