so i got to thinking as i was looing at your spare tire swingout, and the only think i dont like is the spear in the top(never been a fan of sharp points on vehicles -are you entering the runner in "death race"?) have you thought about making that a mounting point for a flag or antenna, say like for a CB or 2m/ham. you could fasion a small flat plate up there to help reflect the signal back up to the antenna, and it would be up high enough to not let the roof or passenger compartment interfere with signal.
i know a lot of guys run the drifter mount, but the big issue with that is it puts the base of the antenna so low it blocks a lot of potential signal. antennas like a large flat plane around them and or to be up high to get good signal. and i think that would be an ideal location, its up close to the top of the roof, its not going to have much of anything to block its signal. if you dont want the antenna up there to be getting smacked all the time you could use a quick disconnect to be able to remove it when not needed. and or if you have a 2m/ham you could get a 40+w receiver and need only say a 6-18" antenna to get some good distance, say like 20miles or so... you could get a bigger antenna that could push over 100 miles if you were in more open terrain say like moab where trees and low hanging branches are not a concern. -antennas even for a 2m are not that hard to change -like 2 min tops.