[chopper]

What Turk said. I just had a new set of tires put on the wife's Miata at a Discount Tire shop here in Mesa. They have a procedure called "road matching" which indexes the tires to the wheel to get the best match of balance and road force. The process involves using a type of spin balance machine which presses a roller against the tire tread while the wheel/tire is spinning, and it measures the force exerted by the tire against the roller as the tire spins. If the variance of force against the roller falls outside of an acceptable allowance, they rotate the tire around the rim (the machine shows how much and which direction) to get the most constant force around the circumference of the tire. Cost was $10 extra per wheel but the Miata is glass smooth on the road with no steering wheel or chassis bounce at all.