Enough mass traveling at enough velocity will eventually negate ANY armor and that thing or any version of it will have to be lightweight (in the category of armored vehicles). I doubt in the next 50 years any version of that thing will be able to take a hit from a rifle chambered in anything 7.62mm or above and keep working. With the proliferation of .50 cal /12.7mm (and thereabouts) sniper rifles in the US civilian population, at least THAT thing won't have a "civilian use."