http://www.forcescience.org/articles/shotinback.pdf
http://www.forcescience.org/articles/tellingthetruth.pdf
http://www.forcescience.org/articles/tempestudy.pdf
Now I realize such things might be a bit over your head, but you'd do well to attempt to understand the research. :)
I only bothered to peruse the first link, but I find little in relation to the dynamics (big word you might need to look up the meaning, look up statics while you're at it, in fact take the college classes, there's statics, dynamics, and strenght of materials all in a row) of people standing or sitting, and 3,000 pound cars traveling at a snail's pace in a parking lot. I know that this concept might be over your head and it might be hard for you to comprehend but attempt to use some common sense first.