"Dear [Savvyhead Name Here], my name is WAR EAGLE. I will be sleeping with you during this session in exchange for repair services. Do not be alarmed, I am a tireless and experienced lover!
XXX OOO,
WAR EAGLE"
I had another idea, maybe this is far off the mark, but it is building off the idea that the armored guy is a one-man gang. I used to be in the Army and knew some tankers, and a tank is a beast that sucks up unbelievable amounts of preventive maintenance and spare parts. Sure, AW is not the game for a careful simulation of combat technology, but I would start off a lot of narration for this player like, "So, Gunhead! You're sitting in your room oiling the lower bogey assembly and working out the kinks in the left knee joint when Boo bursts into your room..."
How 'bout if he gets a "Armor move" that he has to roll for at the start of each session, analogous the moves that hardholders or hocuses get with their people, and if they fail, they get problems with their armor breaking down or attracting unwanted attention?
P.S. Thinking about this character type has made me realize that what I really want is a separate playbook about actual cyborgs, for some full-on Cronenberg style body horror. I gotta work on that.