The dealership told me the metal screeching noise I get from my tires is not covered under my warranty in my new 2012 s60 as its from dirt and grime from getting in the tire. Spraying the tires down with high pressured water doesn't seem to get rid of the noise.

What am i needing to clean and what can I do to prevent having to clean this dirt and grime out of the vehicle all the time? The dealership charges an hourly rate if i get them to do it.

I've never had this issue with other cars I've owned.. what makes the s60's tires more susceptible to dirt and grime?