From a nissan Sentra

Why a sentra... because they looked comfortable, and were super cheap on craigslist.
So, first the passenger seat. Super easy. A couple pieces of 1" angle, some light welding, and drill a few holes.
The drivers seat gave me a bit of trouble, since it is a power seat. Full electric front and rear height, slide, and backrest angle.
Here it is with the slider hardware removed. Im going to make it manual slide, since I keep it pretty much in one place. The other will be there, but not hooked up till I get to wiring it. The old control panel is somewhat in disrepair and needs rebuilt before I can use it. The old driver seat was busted in the back right hand side, the arm had come off the seat frame and made it lean in towards the center console. not comfortable for long drives.
Not many pics of the process, but I linked the front and back brackets on each side together, and you can see how I kept the whole shebang from catching fire. that and a spritzer bottle.
Adjustable headrests, tilting seats (came from a 2 door), adjustable lumbar and driver side adjustable width

They feel 10X better than stock seats.