I finished up the third Battlewagon the other day:
I didn't have as many fitment issues as I did with the last one, with one exception - I couldn't get the "interior wall" to line up quite right. I wasn't that concerned about it, since it can hardly be seen once the model is finished. But, it turns out that it makes a big difference in how the back of the roof fits. I wrestled with it for quite a while and managed to get it pretty close, but in the end I wound up disguising the uglier gaps with some armor plates & rivets made of plasticard:
Another interesting development: GW apparently felt inclined to include an extra sprue along with this model:
...I actually did a double-take when I finished building the model, and had to compare it to my other Battlewagons to be 100% sure that I hadn't lost my mind and forgot to build a large section. Nope, it's just an extra... I guess I'll appreciate having some extra bitz for the future, but I feel bad if there's someone out there who got shorted a sprue in their box...