You can make units immune to it.
Such Grizzly robot tank, and allied MCV
I think it is also important for some of the most powerful units (Apocalypse comes to mind), units that can transport infantry/other units (this includes open-topped vehicles) and units which use the water-state function.
Also, if snipers would be trained to kill drivers, I think all MBT's will get some sort of periscope within a month or so, and as a result the driver shouldn't have to look outside himself so he can't be killed this way. An armor-piercing bullet can still help, but that would only work against lighter-armored units... and not against said MBT's.