Coming back to topic, last December we were driving back from Florida and as we got onto I-79 from Hwy 19 in West Virginia we started getting ridiculous road noise - OK sometimes the road surface and winter tires react, but didn't go away. Probably took a month - checked bearings, alignment, etc etc before mechanic found the bolt in the tire. Still not sure how he missed it as he is very thorough - but it was big enough to make that much noise and we probably put near 1000 miles on the car with no air pressure loss. Still seems odd.