I own a 2001 PT Cruiser with 30,000 miles (yes 30,000 miles!) I have no idea what engine size. I know very little about cars. I first noticed the steering wheel shimming back and forth while driiving. I took it to the local car repair shop and had the wheels aligned and rotated and that seemed to help the problem. The problem came back and the next year I had the same done. This didn't fix the problem this time. Now I hear a whumping from the left front tire area mostly when going over 40 mph. The steering wheel continues to shimmy. The brakes squeak and I have had then looked at twice by the dealership and they said that those kind of brakes do that. Most of my driving is in town stop and go driving. Any suggestions for what might be causing my problems?