Often you won't know if there are. In many cases the property owners will not advertise them as such (eg on Craigslist) but will gladly rent them out to section-8ers since they are a reliable and timely source of rent. One way to tell is to visually look at the house. If it looks like it doesn't fit in with the rest of the neighborhood, and there's no mistake about it, it's likely section8.
What is it with white trash and not getting rid of POS vehicles? Just call the junkman and you get $150 for scrap.
Really pisses me off. The rest of the folks around here take care of their yards, etc. Same family leaves the kid's bikes all over the street, and NEVER mows the yard.