92 and on 124,129,201 and 140(standard) had a tri band antenna installed or available it replaced the existing antenn and and had a splitter attached to it which fed the radio/cell phone.
Once you price this you will forget the excercize.
I would suggest mounting the on glass antenna on the windshield and run the coax down inside the pillar covers to your phone.
Most new phones are triband, with the majority in the 1.8ghz and the antenna is not very large. There are no heating wires, and this type of install is very common on convertibles