We have lived on 7 acres in Jackson County since 2007. The acreage is near I-5, not far from the Calif. border, and is primarily oaks. This year, it appears a mist of fine sap has been dripping from the oaks, covering our cars, and a large rose bush beneath. After washing and waxing the cars yesterday, they are covered again today, as if it was never done. I did an on line search, I see it's a common problem, however with varying opinions on what is happening. Many responders (a lot of them from Texas) say it's not sap but excrement from aphids. Others say it is sap, and you can't stop it until the acorns completely drop and the rains come. We've never had it like this, certainly not all through summer into fall. Can you verify what is happening, and if it IS bug related, what to do about it? Thank you!