Mine are mounted in the steel part of the door. Not real good if you are worried about your door trims or want power windows, but best spot for sound. Kick panels are not real good unless your feet have ears. Otherwise as Agro says, sub behind the seat.
Utes suck to fit speakers in and keep the trim original. I have seen one on here that had split speakers in the dash vents. Might work OK with a sub behind the seats.