I found a great article for you at this site. It is a few pages of explanation. It is right out of the book.
http://books.google.com/books?id=vdcDAAAAMBAJ&pg=PA341&lpg=PA341&dq=ca r+shimmies&source=bl&ots=w9onPYFHFl&sig=GV065ud5H0OSdxCcK4yNZp7ngyw&hl =en&ei=QO-8SreJO8_7tgfGi62LAw&sa=X&oi=book_result&ct=result&resnum=10# v=onepage&q=car%20shimmies&f=false
