Armor and glass
As new fuselage-like parts or as option.
Armor: more armor you add to part more resist to damage taken but more weight(like deadweight but with damage resistance). As example - half armored block will weight twice more but can take 4 more shots before destruction.
Glass - fuselage blocks with changable opacity. Great for cocpits, windows and other stuff.
Clear brush color for windshields!
or wonderwoman jet, klingon cloaking device.....
they really need to add armor
why not have flares too?
Calvin 232 commented
Armour would be sick but so would some new parts allowing new and better ways to fold wings