I've just been checking on the rules pertaining to Infantry attacks against an AFV - specifically the Russian OT Halftrack with just MG firepower.
All AFVs NEVER get any defense values from Terrain when being attacked by non-ordnance.
But Defensive TEM does help an AFV vs. AT weapons.
Nor can they play Concealment.
So there is no point in playing terrain on your own AFV ?!?!
Hill gives a +1 modifier on the attack and gives hull down vs. AT ordnance.
Walls also give hull down advantages (i.e. Only Black RNC are good on To Hit attaempts vs. this AFV.)
Conversely, it is a good thing to lay terrain on an opponent's AFV if liable for Bogging !?!?
Yes, definitely a possible use of certain terrains (woods, stream).
Marsh must be rejected by an AFV, so that can force them back.