Why don't you want to move your target? I live in a neighborhood too but for God sakes man have a little common sense..... I digress.

If your arrowhit the car and it didn't do any damage then its obviously not going very fast.

You could probably stop those things with an old wool blanket or a couple of bedsheets strung up clothesline style. A tarp perhaps....

If you are only trying to stop pass throughs then it would help.But one way or another, at least shoot in a safe direction. No matter what sort of "backstop" you have, an arrow will sooner or later find its way through.

An arrow of mine found its wayunder my block target, through theholes in the chainlink fence, through the woodpile (amazing) and into the slide of my neighborsgrandson's swing set. Of course, no one was in the yard, but it made me remember that the safest shot is the one that is ALWAYS in a safe DIRECTION, not just at a "BACKSTOP".