High-end suspension. I’ve got some Fox Remote Reservoir coilovers on my Tacoma, and besides the off-road performance, they make the thing ride like a cadillac.
That’s not to say they’re soft; I notice drastically reduced body roll in turns (no swaybars) and a tighter chassis feel in general, but I can also hit speedbumps at full speed and not feel a thing, and bumps in the road are just floated over.
I think people would be willing to pay the 1-2k premium for something like this. Maybe they can’t be mass produced easily, or their service life isn’t as long, or whatever, but I can’t ride in another truck without thinking “Damn, this rides so rough.”