They can no longer hide behind a hypothetical tree, but won't automatically be destroyed should they take some fire." - Wienas
What I'm talking about is this:
You don't model the first one as it is impractical to do so, but you could have a whole armored company 50' in front of you and not see it.
The rule as written is: "Vehicles are not obscured simply for being inside area terrain. The 50% rule above takes precedence." The 50% rule being that "At least 50% of the facing of the vehicle that is being targeted...must be hidden by intervening terrain..." I read "intervening terrain" in this case to be the area terrain. So my reasoning is that if 50% of the target facing is blocked by area terrain the vehicle gets obscurement.
For anything to be deliberate the rule should have been written clearer. For instance: "Vehicles are not obscured by area terrain."
Then again, the whole argument is trumped by pg 88 which says "... you should agree with your opponent how to define each piece of terrain you are using...". So if you agree that a forest base is picture 1 then it has grants cover to vehicles, and, if you agree it is picture 2, it does not.
I'm not saying anyone should be forced to play it a certain way. I'm just offering my reasoning at least for the way I play it. There are apparently other places that follow the same reasoning, so its defiantly not an obvious one way or the other rule. I wonder how it's played amongst the "mech is awesome" vs "mech sucks" crowd out on the internet.