Fria Ligans forum

I'm trying to find a rule "I am sure exists" stating that artillery and other overhead attacks are resisted by a vehicle's rear armor (outside the special note for the Javelin.) Any assistance?

Page 115 (Gear chapter) has the following:

ARMOR: The armor levels against weapons fired at the front, sides and rear of the vehicle (page 83). For attacks against the top or bottom, use the rear armor level.

Thanks. I'm also looking for a rule that artillery attacks the top, like Javelins do. "I know it exists," but it might not under an assumption that time fuzes and such are no longer available and artillery is only impact detonating.

(Unrelated to the OP, this is why my houseruled HMMWV armament carriers only improve the rear armor.)