Mostly stock, although it does have a ham radio antenna that adds some drag at speed.
Aero improvements. I live in the country, so I can't surrender totally to the aero gods, as the dirt road gods will leave me stranded, but I want to do what I can.
Cover some grille space on the front
Put in a web across the rear vice the tailgate (or get a fiberglass flush-top for the bed)
Rear wheelwell covers
Radiusing edges on back of front wheelwells