where can i find instructions on how 2 design/make a rubber-band operated car?
Since this is not my area of expertise, I searched Google under the key words "'rubber band car' construction" to get these possible sources:
http://www.plumcreekmarketing.com/articles/16rubberbandcar.html
http://forums.hypography.com/science-projects-homework/7728-rubber-band-powered-car.html
http://ca.answers.yahoo.com/answers2/frontend.php/question?qid=20071205185234AApbtFm
http://www.teachellis.com/main/page_0001.html?inframe=1
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.
I hope this helps. Thanks for asking.