The trunk is a tough area. I too avoid liquid strippers when possible, but use them for intricate areas, like door jams. I apply the stripper, let it work, then scrap off what I can with a putty knife or wire brush. Then I let it dry for a day and remove the rest with a wire wheel. I would cover good paint, because you may possibly throw some active stripper with the wire wheel. Sometimes you get little puddles of stripper in a corner that don't dry all the way through. Better safe than sorry.
In the trunk, I attacked the area around the gas tank and the flat areas on either side with wire wheels-no liquid stripper. These were the only areas I had surface rust. I POR15'd these, let it dry a couple of days, then lightly sanded the POR15 and the rest of the trunk. Then I painted it all. About 20 hours, but it turned out good. My rule of thumb with POR15: if it has rusted in the past 35 years, POR15 it. If it hasn't yet, then primer (or the original paint) and a new coat of paint is adequate. POR15 is not the easiest stuff to work with.
Good luck.