If the 84's are like other years, the trunk release wire is in a plug near the passenger side trunk hinge. on other cars, the wire is already there, even if the release option is not installed. You make have to fish a wire through the trunk down to that area to make use of it. I had to on my 88 coupe.
I also had to add a relay under the dash, and put in a trunk switch. All wires under the dash were already there.