I get a shimmy felt through the steering wheel in my '01 Catera between 50-60mph. The car runs great, and is in perfect alignment. I've also had the wheels balanced. I've searched the forum for this issue and have read many opinions on what the cause is, but haven't really been able to boil them down to anything conclusive. So, is there a definitive answer as to the cause of this??? Is it something inherent in the car, or something that I need to have fixed?