Cool, you’re way ahead of me.
Honestly, I think you can wing it for the most part, or have a dialogue about it when it turns up. I suspect there will be times when it will work well to treat it like a vehicle and times when it will make more sense to treat the character like a person who maybe has some armor. Much of it can probably be handled with fictional positioning.
I would take a look at the Road War moves and try to figure out how to best apply them. Deal With Bad Terrain and Shoulder Another Vehicle probably work as-is (though there may be differences in when the fiction dictates they should come into play compared to someone driving a car), while Outdistance and Overtake are probably less relevant (unless this exoskeleton is really fast, or in situations where they’re racing against other vehicles with similar speeds). Or maybe they work fine if the exoskeleton just has very low speed? I haven’t looked at that part.
The more I look at it, the more I think you’ll be fine treating it as a regular vehicle that probably just has a low speed? Maybe give it speed -1 in exchange for something else?