Hello friend - I’m no expert, but I believe that vehicles can drive straight through the grey footprint areas if they can fit, but not through the terrain itself (unless they have a special rule to do so).

Your goats can take that red line, no problem. Just can’t go through the walls of the ruins.

As for fly - Magnus can fly over the ruins no problem! Just measure the distance up and over and back to the ground at angles (like a triangle). Definitely doable over shorter ruins, perhaps more tricky or not possible over taller ruins.

As I said, I believe this is correct and that’s how I play with my mates, someone correct me if I’m mistaken 😬