I have a 2000 S430 Mercedes. I purchased it used with 186,000 miles. The car is beautiful!! Inside and out looks almost brand new. When i got the car it had the 18 inch staggered AMG wheels on it, but the tire size was wrong and they were badly bald. I replaced the tires with 245/45/18 in the front & 265/40/18 in the back. I drove the car on the highway & there was & still is a terrible shaking of the front wheels and the steering wheel,at this point im think goodyear didn't balance my tires went back to goodyear they check and then they tell me that the balance is good but i need a alignment,so i tell them go ahead and do it, then they tell me they did a horizontal alignment to make sure my front wheels tracking straight but they couldn't do a vertical alignment because the top part of my front wheels are leaning slightly inward and they don't know why. I don't know why either but any advice or suggestions would be appreciated....Thanks