+1 on the steel kevlar sandwich. Use a bedcoating like por or rhinoliner as the media to water proof in between layers . The first steel sheet opens up the projectile the kevlar catches the spalling and the last sheet catches any residual. I'm not saying this would stop 50 cal but it would be useful against small arms fire. Protecting the glass areas would be harder and You might want to relocate the radiator or build a angled "bullet trap" in front of it. Then you would have to invest in runflats or foam fill the tires which means no highway driving. Or you could just build a bunker in your house load it up with all the stuff you need and just not go outside. 8 feet of dirt is effecive against ALL rifle and small arms rounds!