All i can say is oh dear god, good luck. I considder myself pretty good at wrapping interior items, have done door handles, guage pods, various other plastic bits, even an iphone and sky remote, but when i tried to do my roof last weekend (with quality Hexis vinyl i might add) all i ended up with was a massive wrinkled mess.
The Zeds roof is an absolute nightmare IMO as if you start in the corner, as i beleive yoyu shoud, the vinyl has to stretch in 3 different directions and planes.
Im dont have any figures as for the length of the wrap, the roof iirc is about 1.5-2m alone, so id guess somewhere between 15-20M but i could be way off. Best wait for RT to pop in