I have no seats in mine.. but I want to put a single seat on the passenger side and then get the other seat trim and seat from the wreckers to get the fabric off it to make it really look like a small sub box to mimic a folded seat.... factory look modding...
I would use a shallow mount sub.. and since its a small truck I wouldn't make the box huge.. just after a little bass.. I don't need the brain scrambling mega stereo I used to have... not that I still don't enjoy it.. I just don't need it as much as the truck space.