Again, I tried to buy pieces of terrain that I could sit on the official sized terrain, keeping those who like the terrain to be correctly sized happy campers. These two pieces will fit quite well on the B5 blocking terrain. I'll probably get a couple of barrels as well, paint them, and stick a few radioactive decals to them (they sell decals as well, which are nice). Stick those between these two pieces of terrain, and I have a nice filler for this blocking terrain.
Also you probably could implement some of the random rules I've heard chatted over on the MW forums. That is, exploding tanks. You could pop these puppies from a distance, doing damage (or lingering radioactive damage I suppose) to surrounding units. House rules are fun!
Noone better actually pop these open though, or I'll club them in the head with the remnants. To much time and effort to paint these guys! ; )